> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-mintlify-fbfa8bee.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# 2025 Changelog
> Changelog for 2025
### Table of Contents
**[ClickHouse release v25.12, 2025-12-18](#2512)**
**[ClickHouse release v25.11, 2025-11-27](#2511)**
**[ClickHouse release v25.10, 2025-10-30](#2510)**
**[ClickHouse release v25.9, 2025-09-25](#259)**
**[ClickHouse release v25.8 LTS, 2025-08-28](#258)**
**[ClickHouse release v25.7, 2025-07-24](#257)**
**[ClickHouse release v25.6, 2025-06-26](#256)**
**[ClickHouse release v25.5, 2025-05-22](#255)**
**[ClickHouse release v25.4, 2025-04-22](#254)**
**[ClickHouse release v25.3 LTS, 2025-03-20](#253)**
**[ClickHouse release v25.2, 2025-02-27](#252)**
**[ClickHouse release v25.1, 2025-01-28](#251)**
**[Changelog for 2024](/resources/changelogs/oss/2024)**
**[Changelog for 2023](/resources/changelogs/oss/2023)**
**[Changelog for 2022](/resources/changelogs/oss/2022)**
**[Changelog for 2021](/resources/changelogs/oss/2021)**
**[Changelog for 2020](/resources/changelogs/oss/2020)**
**[Changelog for 2019](/resources/changelogs/oss/2019)**
**[Changelog for 2018](/resources/changelogs/oss/2018)**
**[Changelog for 2017](/resources/changelogs/oss/2017)**
ClickHouse release 25.12, 2025-12-18
#### Backward Incompatible Change
* ALTER MODIFY COLUMN now requires explicit DEFAULT when converting nullable columns to non-nullable types. Previously such ALTERs could get stuck with cannot convert null to not null errors, now NULLs are replaced with column's default expression. Resolves [#5985](https://github.com/ClickHouse/ClickHouse/issues/5985). [#84770](https://github.com/ClickHouse/ClickHouse/pull/84770) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Ngram tokenizer will no longer return ngrams less than the length N it was set with. Text Search will return no rows when search tokens are empty. [#89757](https://github.com/ClickHouse/ClickHouse/pull/89757) ([George Larionov](https://github.com/george-larionov)).
* When alter column from `String` to `Nullable(String)`, we will not do mutation to the data. But for `uniq` aggregate function, it use different data strucuture: for nullable column, it will use `AggregateFunctionNull` with a nested uniq aggregator. the `AggregateFunctionNull` will serialize an extra bool flag. This will make the statistics file incompatible. The fix is add a flag to record if it is a nullable column during serialization. The format of statisticis has changed, and the server can fail if we have statistics with old format. This PR [#90904](https://github.com/ClickHouse/ClickHouse/pull/90904) will fix the crash, and throw exception when the existing statisticis uses lagecy format. To avoid exception, we should run `ALTER TABLE table MATERIALIZE STATISTICS ALL` to regenerate the statistics to fix it. [#90311](https://github.com/ClickHouse/ClickHouse/pull/90311) ([Han Fei](https://github.com/hanfei1991)).
* Remove settings `allow_not_comparable_types_in_order_by`/`allow_not_comparable_types_in_comparison_functions`. Allowing non-comparable types in order by or comparison functions may lead to logical errors and unexpected results. Resolves [#90028](https://github.com/ClickHouse/ClickHouse/issues/90028). [#90527](https://github.com/ClickHouse/ClickHouse/pull/90527) ([Pavel Kruglov](https://github.com/Avogar)).
* Changed the default of setting `check_query_single_value_result` from `true` to `false`. This causes `CHECK TABLE` to return detailed per-part results instead of an aggregated result (1 = okay, 0 = errors found). Compared to the previous behavior, this is likely more aligned with what the user wants. [#91009](https://github.com/ClickHouse/ClickHouse/pull/91009) ([Robert Schulze](https://github.com/rschu1ze)).
* Multiple fixes around implicit indices. The schema shown or stored (keeper metadata) won't include implicit indices, such as the ones created by settings `add_minmax_index_for_numeric_columns` or `add_minmax_index_for_string_columns`. This might cause metadata errors when a ReplicatedMergeTree table is created or updated in a newer version, while there is a replica in an older release. For those cases send DDLs to the old replica until the cluster is upgraded completely. [#91429](https://github.com/ClickHouse/ClickHouse/pull/91429) ([Raúl Marín](https://github.com/Algunenano)).
* Update clickhouse-client to return a non-zero exit code (159 - TIMEOUT\_EXCEEDED) when a query times out due to `receive_timeout`. Previously, timeouts would return exit code 0 (success), making it difficult for scripts and automation to detect timeout failures. [#91432](https://github.com/ClickHouse/ClickHouse/pull/91432) ([Sav](https://github.com/sberss)).
* It is now forbidden to create special `MergeTree` tables (such as `ReplacingMergeTree`, `CollapsingMergeTree`, etc.) with an empty `ORDER BY` key, since merge behavior in these tables is undefined. If you still need to create such a table, enable the `allow_suspicious_primary_key` setting. [#91569](https://github.com/ClickHouse/ClickHouse/pull/91569) ([Anton Popov](https://github.com/CurtizJ)).
* Fix functions `bitShiftLeft` and `bitShiftRight` to return 0 or empty value in case of a shift exactly of the size of the type. [#91943](https://github.com/ClickHouse/ClickHouse/pull/91943) ([Pablo Marcos](https://github.com/pamarcos)).
* Follow-up to [#88380](https://github.com/ClickHouse/ClickHouse/pull/88380). This PR marks disabled positional arguments in the projections as a backward-incompatible change. Additionally, it introduces the `enable_positional_arguments_for_projections` setting to enable a safe ClickHouse cluster upgrade when positional arguments are present in the projections. [#92007](https://github.com/ClickHouse/ClickHouse/pull/92007) ([Dmitry Novik](https://github.com/novikd)).
* Enable advanced shared data for JSON by default. After that change downgrade to versions before 25.8 will be not possible, because these versions won't be able to read new data parts with JSON column. For safe upgrades, it's recommended to set `compatibility` setting to the previous version or set MergeTree settings `dynamic_serialization_version='v2', object_serialization_version='v2'`. [#92511](https://github.com/ClickHouse/ClickHouse/pull/92511) ([Pavel Kruglov](https://github.com/Avogar)).
#### New Feature
* Users can now configure S3/Azure Queue tables to move or tag processed files, in addition to the previous options to keep or remove files. Resolves [#72944](https://github.com/ClickHouse/ClickHouse/issues/72944). [#86907](https://github.com/ClickHouse/ClickHouse/pull/86907) ([Murat Khairulin](https://github.com/mxwell)).
* In storage S3/Azure Queue add setting `commit_on_select` (to define whether processed data needs to be committed and whether to apply `after_processing` action). The default value is `false`, fix check for attached mv during select. [#91450](https://github.com/ClickHouse/ClickHouse/pull/91450) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Add instrumentation at runtime using XRay to debug issues in production and profile deterministically. Resolves [#74249](https://github.com/ClickHouse/ClickHouse/issues/74249). [#89173](https://github.com/ClickHouse/ClickHouse/pull/89173) ([Pablo Marcos](https://github.com/pamarcos)).
* Allows the use of non-constant second arguments for `IN`. It also supports a tuple as a second argument. [#77906](https://github.com/ClickHouse/ClickHouse/pull/77906) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Functions to calculate area and perimeter for the geometry type. [#89047](https://github.com/ClickHouse/ClickHouse/pull/89047) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Implement `dictGetKeys` function that returns the dictionary key(s) whose attribute equals the specified value. It uses a per-query reverse-lookup cache, tuned by the `max_reverse_dictionary_lookup_cache_size_bytes` setting, to speed up repeated lookups. [#89197](https://github.com/ClickHouse/ClickHouse/pull/89197) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Add setting `type_json_skip_invalid_typed_paths` to disable exceptions for inserts/type casts to JSON type when input JSON cannot be cast to explicit typed paths in JSON type. Falls back to null/zero value of typed path. [#89886](https://github.com/ClickHouse/ClickHouse/pull/89886) ([Max Justus Spransy](https://github.com/maxjustus)).
* Support `direct` (nested loop) join for MergeTree tables. To use it, specify it as the single option in the setting: `join_algorithm = 'direct'`. [#89920](https://github.com/ClickHouse/ClickHouse/pull/89920) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Support `ORDER BY` in `CREATE` operation for iceberg + sorting in `INSERT`. Resolves [#89916](https://github.com/ClickHouse/ClickHouse/issues/89916). [#90141](https://github.com/ClickHouse/ClickHouse/pull/90141) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Introduce projection-level settings, exposed through the new `WITH SETTINGS` clause in `ALTER TABLE ... ADD PROJECTION`. These settings allow projections to override certain MergeTree storage parameters (e.g. `index_granularity`, `index_granularity_bytes`) on a per-projection basis. [#90158](https://github.com/ClickHouse/ClickHouse/pull/90158) ([Amos Bird](https://github.com/amosbird)).
* Add `HMAC(algorithm, message, key)` sql function as a part of [#73900](https://github.com/ClickHouse/ClickHouse/issues/73900) and [#38775](https://github.com/ClickHouse/ClickHouse/issues/38775). [#90837](https://github.com/ClickHouse/ClickHouse/pull/90837) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
* Add support for `has` function to use primary key and data skipping indexes when first argument is constant array. Closes [#90980](https://github.com/ClickHouse/ClickHouse/issues/90980). [#91023](https://github.com/ClickHouse/ClickHouse/pull/91023) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Implement new input output format `Buffers`. This format is similar to `Native`; however, unlike `Native`, it does not store column names, column types, or any extra metadata. Closes [#84017](https://github.com/ClickHouse/ClickHouse/issues/84017). [#91156](https://github.com/ClickHouse/ClickHouse/pull/91156) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Add a setting `max_streams_for_files_processing_in_cluster_functions` to control number of streams for parallel files reading in Cluster table functions. Closes [#90223](https://github.com/ClickHouse/ClickHouse/issues/90223). [#91323](https://github.com/ClickHouse/ClickHouse/pull/91323) ([Pavel Kruglov](https://github.com/Avogar)).
* Data masking for Row-level security (only available in ClickHouse Cloud). Add data masking policy parser to support it in clickhouse-client. [#90552](https://github.com/ClickHouse/ClickHouse/pull/90552) ([pufit](https://github.com/pufit)).
* Add `allow_reentry` option to `windowFunnel` aggregate function. When enabled with strict\_order, it ignores events that violate the order instead of stopping the funnel analysis. This enables handling user journeys with refreshes (A->A->B) or back-navigation (A->B->A->C) without underreporting conversion rates. [#86916](https://github.com/ClickHouse/ClickHouse/pull/86916) ([Lee ChaeRok](https://github.com/LeeChaeRok)).
* Keeper compatibility with zookeeper: create with statistics. [#88797](https://github.com/ClickHouse/ClickHouse/pull/88797) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Support for ZooKeeper persistent watches in ClickHouse Keeper. Continuation part 2: [https://github.com/ClickHouse/ClickHouse/pull/78207](https://github.com/ClickHouse/ClickHouse/pull/78207). [#88813](https://github.com/ClickHouse/ClickHouse/pull/88813) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Add a MergeTree setting `alter_column_secondary_index_mode` to control what to do with indices during mutations. Possible values: throw, drop, rebuild, and compatibility. Closes [#77797](https://github.com/ClickHouse/ClickHouse/issues/77797). [#89335](https://github.com/ClickHouse/ClickHouse/pull/89335) ([Raúl Marín](https://github.com/Algunenano)).
* As `Time` and `Time64` data types are production ready, the setting `enable_time_time64_type` is now enabled by default. [#89345](https://github.com/ClickHouse/ClickHouse/pull/89345) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Support reading DeltaLake CDF via `deltaLake` table function with settings `delta_lake_snapshot_start_version`, `delta_lake_snapshot_end_version`. The CDF (Change Data Feed, a feature that lets you automatically capture and query row-level data changes—such as inserts, updates, and deletes—between versions of a Delta table) is enabled in DeltaLake via `delta.enableChangeDataFeed`. The columns provided along with the data are `_change_type`, `_commit_version`, `_commit_timestamp`. [#90431](https://github.com/ClickHouse/ClickHouse/pull/90431) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Support negative indexes for tuple element access (e.g. `tuple.-1`). [#91665](https://github.com/ClickHouse/ClickHouse/pull/91665) ([Amos Bird](https://github.com/amosbird)).
#### Experimental Feature
* Introduce Text index format v3 and promote it to Beta status.
* The new logic is introduced to automatically execute queries using parallel replicas, controlled by the setting `automatic_parallel_replicas_mode`. During normal single-node execution, ClickHouse collects statistics that will later be considered during the planning stage. If statistics suggest that parallel replicas are likely to be beneficial, ClickHouse will automatically execute the given query with parallel replicas. The set of supported queries is currently fairly limited. [#87541](https://github.com/ClickHouse/ClickHouse/pull/87541) ([Nikita Taranov](https://github.com/nickitat)).
* Access ClickHouse Cloud instances using Cloud credentials with --login. [#89261](https://github.com/ClickHouse/ClickHouse/pull/89261) ([Krishna Mannem](https://github.com/kcmannem)).
* Adds session-level setting `aggregate_function_input_format` to improve `INSERT` queries into tables with `AggregateFunction` columns, allowing insertion of data as serialized state, raw values, or arrays. [#88088](https://github.com/ClickHouse/ClickHouse/pull/88088) ([Punith Nandyappa Subashchandra](https://github.com/punithns97)).
#### Performance Improvement
* Optimize `ORDER BY...LIMIT N` queries by using skip index and dynamic threshold filter to significantly reduce rows processed. [#89835](https://github.com/ClickHouse/ClickHouse/pull/89835) ([Shankar Iyer](https://github.com/shankar-iyer)).
* ClickHouse now uses skip indexes to perform index analysis on WHERE clauses with mixed `AND`- and `OR`-connected filter conditions. Previously, the WHERE clause needed to be a conjunction (AND) of filter conditions to utilize skip indexes. A new setting `use_skip_indexes_for_disjunctions` (default: on) controls this feature. (issue [#75228](https://github.com/ClickHouse/ClickHouse/issues/75228)). [#87781](https://github.com/ClickHouse/ClickHouse/pull/87781) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Support keeping reading in order from the left table in LEFT/INNER JOIN operations, which can be utilized by subsequent steps. Can be disabled using setting `query_plan_read_in_order_through_join`. Support virtual row while reading optimization (see setting `read_in_order_use_virtual_row`) for LEFT/INNER JOINs. [#89815](https://github.com/ClickHouse/ClickHouse/pull/89815) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Improve the performance of lazily materialized columns with a bigger limit. [#90309](https://github.com/ClickHouse/ClickHouse/pull/90309) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Users should see lower latency in index analysis when large `minmax` indexes (millions of granules) are present. [#90428](https://github.com/ClickHouse/ClickHouse/pull/90428) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Implement simple DPsize join reordering algorithm for INNER JOINs. A new experimental setting controls what algorithms are used in which order, e.g. `query_plan_optimize_join_order_algorithm='dpsize,greedy'` means that DPsize is tried first with fallback to greedy. [#91002](https://github.com/ClickHouse/ClickHouse/pull/91002) ([Alexander Gololobov](https://github.com/davenger)).
* Fail fast when queries reach row limits. Resolves [#61872](https://github.com/ClickHouse/ClickHouse/issues/61872). [#62804](https://github.com/ClickHouse/ClickHouse/pull/62804) ([Sean Haynes](https://github.com/seandhaynes)).
* [#84477](https://github.com/clickhouse/clickhouse/pull/84477) added constrains regarding select queries which can be used in `insert select from s3Cluster(...)` queries for parallel distributed execution. this change allows using where, which was possible before. [#84611](https://github.com/ClickHouse/ClickHouse/pull/84611) ([Igor Nikonov](https://github.com/devcrafter)).
* Prefetch keys during hash table iteration to minimize cache misses. [#84708](https://github.com/ClickHouse/ClickHouse/pull/84708) ([lgbo](https://github.com/lgbo-ustc)).
* Optimize the `histogram` aggregate function by sorting only the tail of points array and skipping sort for monotonic inputs, achieving \~10% speedup. [#85760](https://github.com/ClickHouse/ClickHouse/pull/85760) ([MakarDev](https://github.com/MakarDev)).
* Improved filtering performance for predicates with functions such as `like`, `equals`, `has`, and others by leveraging an additional preliminary filter built from the text index. This optimization is enabled via the `query_plan_text_index_add_hint` setting. Improved usage of the text index for columns of `Map` data type. [#88550](https://github.com/ClickHouse/ClickHouse/pull/88550) ([Anton Popov](https://github.com/CurtizJ)).
* Optimize repeated inverse dictionary lookups by doing faster lookups into a precomputed set of possible key values. Closes [#7968](https://github.com/ClickHouse/ClickHouse/issues/7968). [#88971](https://github.com/ClickHouse/ClickHouse/pull/88971) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Improve `topK` aggregate function performance and behaviour. [#90091](https://github.com/ClickHouse/ClickHouse/pull/90091) ([Raúl Marín](https://github.com/Algunenano)).
* Improved performance of `Decimal` comparison operations. Resolves [#28192](https://github.com/ClickHouse/ClickHouse/issues/28192). [#90153](https://github.com/ClickHouse/ClickHouse/pull/90153) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Support partition pruning for Apache Paimon functions, continuing from [https://github.com/ClickHouse/ClickHouse/pull/84423](https://github.com/ClickHouse/ClickHouse/pull/84423). [#90253](https://github.com/ClickHouse/ClickHouse/pull/90253) ([JIaQi](https://github.com/JiaQiTang98)).
* Use advanced SIMD operations for logical functions via dynamic dispatch. [#90432](https://github.com/ClickHouse/ClickHouse/pull/90432) ([Raúl Marín](https://github.com/Algunenano)).
* Improve JIT function performing by not initializing the result column to zero unnecessarily. [#90449](https://github.com/ClickHouse/ClickHouse/pull/90449) ([Raúl Marín](https://github.com/Algunenano)).
* Speed up `T64` decompression via dynamic dispatch. [#90610](https://github.com/ClickHouse/ClickHouse/pull/90610) ([Raúl Marín](https://github.com/Algunenano)).
* Optimize MergeTree reader inplace filtering. Resolves [#87119](https://github.com/ClickHouse/ClickHouse/issues/87119). [#90630](https://github.com/ClickHouse/ClickHouse/pull/90630) ([Xiaozhe Yu](https://github.com/wudidapaopao)).
* Introduce an additional heuristic to reduce the widths of the selected merge choices. Performing more narrow merges will increase write amplification, but at the same time, can help prevent falling under the `TOO_MANY_PARTS` errors. [#91163](https://github.com/ClickHouse/ClickHouse/pull/91163) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Improve query performance for S3 tables created with glob pattern by pushing down `_path` filter values, which allows to avoid S3 listing operations. Controlled by the `s3_path_filter_limit` setting. [#91165](https://github.com/ClickHouse/ClickHouse/pull/91165) ([Eduard Karacharov](https://github.com/korowa)).
* Speed up converting columns to bool (in WHERE clauses) via dynamic dispatch. [#91203](https://github.com/ClickHouse/ClickHouse/pull/91203) ([Raúl Marín](https://github.com/Algunenano)).
* Speed up sorting of single numeric block via dynamic dispatch. [#91213](https://github.com/ClickHouse/ClickHouse/pull/91213) ([Raúl Marín](https://github.com/Algunenano)).
* Add optimization to remove unused columns in query plans. Resolves [#75152](https://github.com/ClickHouse/ClickHouse/issues/75152). [#76487](https://github.com/ClickHouse/ClickHouse/pull/76487) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* The default value of `query_plan_optimize_join_order_limit` is changed to `10`. [#89312](https://github.com/ClickHouse/ClickHouse/pull/89312) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Enable the setting `allow_statistics_optimize` by default, so the JOINs optimizer will use column statistics. [#89332](https://github.com/ClickHouse/ClickHouse/pull/89332) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Support JOIN runtime filters for `ANTI` JOINs. Also, refactor the runtime filters implementation to reduce lock contention. [#89710](https://github.com/ClickHouse/ClickHouse/pull/89710) ([Dmitry Novik](https://github.com/novikd)).
* Reduces memory usage during merges in `system.metric_log` table (enabled by default) by setting `min_bytes_for_wide_part` and `vertical_merge_algorithm_min_bytes_to_activate` to 128MB. [#89811](https://github.com/ClickHouse/ClickHouse/pull/89811) ([filimonov](https://github.com/filimonov)).
* Enable using inverted index in PREWHERE. Resolves [#89975](https://github.com/ClickHouse/ClickHouse/issues/89975). [#89977](https://github.com/ClickHouse/ClickHouse/pull/89977) ([Peng Jian](https://github.com/fastio)).
* Don't add S3 providers if GCP OAuth is used which improves performance on GCS. [#91706](https://github.com/ClickHouse/ClickHouse/pull/91706) ([Antonio Andelic](https://github.com/antonio2368)).
#### Improvement
* Added a new setting `apply_row_policy_after_final` that allows the query to apply row policy only after final, which will make the behavior for ReplacingMergeTree with row policies more correct. Fixes [#90986](https://github.com/ClickHouse/ClickHouse/issues/90986). [#91065](https://github.com/ClickHouse/ClickHouse/pull/91065) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* In `Pretty` format, named tuples are now displayed as Pretty JSON. This closes [#65022](https://github.com/ClickHouse/ClickHouse/issues/65022). [#91779](https://github.com/ClickHouse/ClickHouse/pull/91779) ([Mostafa Mohamed Salah](https://github.com/Sasao4o)).
* Added fields `last_error_time`, `last_error_message`, `last_error_query_id` and `last_error_trace` to `system.error_log` table. [#89879](https://github.com/ClickHouse/ClickHouse/pull/89879) ([Narasimha Pakeer](https://github.com/npakeer)).
* CLI client can now suppress the 'ClickHouse server version is older than ClickHouse client. It may indicate that the server is out of date and can be upgraded' message by specifying `--no-server-client-version-message` or `false`. [#87784](https://github.com/ClickHouse/ClickHouse/pull/87784) ([Larry Snizek](https://github.com/larry-cdn77)).
* Add error message that the part was deduplicated. [#80264](https://github.com/ClickHouse/ClickHouse/pull/80264) ([Aleksandr Musorin](https://github.com/AVMusorin)).
* Added `dependencies` and `missing_dependencies` columns to `system.kafka_consumers` to report materialized view target tables for Kafka tables. Added `KafkaMVNotReady` counter. [#85346](https://github.com/ClickHouse/ClickHouse/pull/85346) ([Ilya Golshtein](https://github.com/ilejn)).
* Now, table's default expressions work correctly with insertions using remote and native protocol. Closes [#87972](https://github.com/ClickHouse/ClickHouse/issues/87972). [#88540](https://github.com/ClickHouse/ClickHouse/pull/88540) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Allow disabling of `PSI_*_*` async metrics collection. [#88557](https://github.com/ClickHouse/ClickHouse/pull/88557) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* Added support of sparse serialization for columns of `Nullable` type. This continues [#44539](https://github.com/ClickHouse/ClickHouse/issues/44539). [#88999](https://github.com/ClickHouse/ClickHouse/pull/88999) ([Amos Bird](https://github.com/amosbird)).
* `plain-rewritable` disk has its own implementation and layout. Let's not base it on top of regular `plain` disks. [#89807](https://github.com/ClickHouse/ClickHouse/pull/89807) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Any exception in HTTP should never contain final zero chunk. [#89998](https://github.com/ClickHouse/ClickHouse/pull/89998) ([Kaviraj Kanagaraj](https://github.com/kavirajk)).
* Add a keeper-server-side check during handshake to reject clients when `last_zxid_seen (provided by the client) > last_processed_zxid`. This prevents stale reads when clients reconnect to lagging replicas. [#90016](https://github.com/ClickHouse/ClickHouse/pull/90016) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Add `kafka_consumer_reschedule_ms` as a tunable `Kafka` table engine setting in order to adjust how long consumers sleep for new data. Resolves [#89204](https://github.com/ClickHouse/ClickHouse/issues/89204). [#90112](https://github.com/ClickHouse/ClickHouse/pull/90112) ([Jeremy Aguilon](https://github.com/JerAguilon)).
* Add a new column `parts_in_progress_names` to `system.mutations` to improve diagnostics. [#90155](https://github.com/ClickHouse/ClickHouse/pull/90155) ([Shaohua Wang](https://github.com/tiandiwonder)).
* Retry network errors when S3 library parses an XML response. [#90216](https://github.com/ClickHouse/ClickHouse/pull/90216) ([Sema Checherinda](https://github.com/CheSema)).
* We want to run keepers in a separate server processes and, to avoid overwhelming Prometheus in large regions, we should continue to expose only keeper-related metrics. [#90244](https://github.com/ClickHouse/ClickHouse/pull/90244) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Add support for loading ClickHouse Client configuration from XDG Base Directory paths (e.g., `~/.config/clickhouse/config.xml`) in addition to the legacy `~/.clickhouse-client/` location. Resolves [#89882](https://github.com/ClickHouse/ClickHouse/issues/89882). [#90306](https://github.com/ClickHouse/ClickHouse/pull/90306) ([Wujun Jiang](https://github.com/rainac1)).
* Add byte size limit for append request batch in Keeper. Limit is controlled with `keeper_server.coordination_settings.max_requests_append_bytes_size`. [#90342](https://github.com/ClickHouse/ClickHouse/pull/90342) ([Antonio Andelic](https://github.com/antonio2368)).
* Add a setting for Iceberg to prevent large partitions count. [#90365](https://github.com/ClickHouse/ClickHouse/pull/90365) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Update warning messages when approaching guardrails limits: show current and throw values. [#90438](https://github.com/ClickHouse/ClickHouse/pull/90438) ([Nikita Fomichev](https://github.com/fm4v)).
* Stream chunks in `system.filesystem_cache` table instead of creating a single chunk with all cache state. Reading filesystem cache state can take a long time for large caches and consume a lot of memory, so streaming it is indispensable for large deployments. [#90508](https://github.com/ClickHouse/ClickHouse/pull/90508) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix bad exception message in Hive partitioning: it was missing a space. [#90685](https://github.com/ClickHouse/ClickHouse/pull/90685) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Entries in the vector similarity index cache are now removed when table parts are dropped or replaced by newer parts. Prior to this, these would be cleared only lazily by cache eviction. [#90750](https://github.com/ClickHouse/ClickHouse/pull/90750) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Bump chdig (a command-line ClickHouse diagnostic tool) to [v25.12.1](https://github.com/azat/chdig/releases/tag/v25.12.1). [#91394](https://github.com/ClickHouse/ClickHouse/pull/91394) ([Azat Khuzhin](https://github.com/azat)).
* Now pre-signed URLs work with S3. Closes [#65032](https://github.com/ClickHouse/ClickHouse/issues/65032). [#90827](https://github.com/ClickHouse/ClickHouse/pull/90827) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* The text index now works with `ReplacingMergeTree` tables. [#90908](https://github.com/ClickHouse/ClickHouse/pull/90908) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Avoid exposing the ClickHouse server version in HTTP error responses returned before authentication. [#91003](https://github.com/ClickHouse/ClickHouse/pull/91003) ([filimonov](https://github.com/filimonov)).
* Now `HTTP_CONNECTION_LIMIT_REACHED` exception would be thrown when `hard_limit` for the http clients connection is reached. It is set as `20000` for the disk connections. [#91016](https://github.com/ClickHouse/ClickHouse/pull/91016) ([Sema Checherinda](https://github.com/CheSema)).
* Introduce `system.background_schedule_pool{,_log}` to improve introspection of background jobs. [#91157](https://github.com/ClickHouse/ClickHouse/pull/91157) ([Azat Khuzhin](https://github.com/azat)).
* You can now quickly comment or uncomment your currently selected lines in the Web UI query editor using `Ctrl+/` (or `Cmd+/` on Mac), making it easier to temporarily disable parts of your query while testing. [#91160](https://github.com/ClickHouse/ClickHouse/pull/91160) ([Samuel K.](https://github.com/OpenGLShaders)).
* Add `system.completions` to the list of always accessible tables. [#91166](https://github.com/ClickHouse/ClickHouse/pull/91166) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Add profile events `FailedInitialQuery` and `FailedInitialSelectQuery`. [#91172](https://github.com/ClickHouse/ClickHouse/pull/91172) ([RinChanNOW](https://github.com/RinChanNOWWW)).
* Fixed potential thread pool starvation when reading column samples for JSON columns with many subcolumns by respecting the `merge_tree_use_prefixes_deserialization_thread_pool` setting instead of unconditionally using the thread pool. [#91208](https://github.com/ClickHouse/ClickHouse/pull/91208) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Support `JSON` type in `tupleElement`. Closes [#81630](https://github.com/ClickHouse/ClickHouse/issues/81630). [#91327](https://github.com/ClickHouse/ClickHouse/pull/91327) ([Pavel Kruglov](https://github.com/Avogar)).
* Fixed spurious memory limit errors when userspace page cache is enabled. [#91361](https://github.com/ClickHouse/ClickHouse/pull/91361) ([Michael Kolupaev](https://github.com/al13n321)).
* Ngrams tokenizer can now be built with ngram\_length = 1. [#91529](https://github.com/ClickHouse/ClickHouse/pull/91529) ([George Larionov](https://github.com/george-larionov)).
* Support storage settings inside functions in `INSERT INTO FUNCTION`, similar to how they are already supported for `SELECT`. Closes [#89386](https://github.com/ClickHouse/ClickHouse/issues/89386). [#91707](https://github.com/ClickHouse/ClickHouse/pull/91707) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Throw "not implemented" for truncate query for data lakes instead of silently doing nothing. Closes [#86604](https://github.com/ClickHouse/ClickHouse/issues/86604). [#91713](https://github.com/ClickHouse/ClickHouse/pull/91713) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Set max message size on parquet v3 reader to avoid getting `DB::Exception: apache::thrift::transport::TTransportException: MaxMessageSize reached`. [#91737](https://github.com/ClickHouse/ClickHouse/pull/91737) ([Arthur Passos](https://github.com/arthurpassos)).
* Add a setting `insert_select_deduplicate`. Which makes it more clear how do we handle insert deduplication when INSERT SELECT. In general it is not possible to do deduplication for such queries, but if the table is not changed and the result is sorted then it is possible to do deduplication on retry. We could not track that the source is the same. But we could check that the result of select query is sorted. Actually it turned out that in general case it is really hard to check, but the simple case with `ORDER BY ALL` is easy. Right now the logic here actually is broken. We try to deduplicate, but in the most cases it just does not see duplicates among the blocks because the select returns different data. [#91830](https://github.com/ClickHouse/ClickHouse/pull/91830) ([Sema Checherinda](https://github.com/CheSema)).
* Allow implicit type conversion when casting `Array` to `QBit`. Integer and float arrays can now be inserted directly into `QBit` columns without explicit type casts. [#91846](https://github.com/ClickHouse/ClickHouse/pull/91846) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Add `CapnProto` message size limit. It can be changed with `format_capn_proto_max_message_size`. [#91888](https://github.com/ClickHouse/ClickHouse/pull/91888) ([Antonio Andelic](https://github.com/antonio2368)).
* Refine mark cache metrics to track only queries (after [#83415](https://github.com/ClickHouse/ClickHouse/issues/83415) `MarkCacheHits`/`MarkCacheMisses` was updated for merges as well, this PR will revert this behavior back). [#91910](https://github.com/ClickHouse/ClickHouse/pull/91910) ([Azat Khuzhin](https://github.com/azat)).
* Fix `client_info.interface` being set to `TCP` for local connections. [#91933](https://github.com/ClickHouse/ClickHouse/pull/91933) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* `refresh_certificates_task_interval` parameter in ACME client configuration now expects a value in seconds. [#92211](https://github.com/ClickHouse/ClickHouse/pull/92211) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Log parts events in `system.part_log` for `system.*_log`. [#92217](https://github.com/ClickHouse/ClickHouse/pull/92217) ([Azat Khuzhin](https://github.com/azat)).
#### Bug Fix (user-visible misbehavior in an official stable release)
* Fixes some bugs with PREWHERE involving supertypes for `Time` and `Time64` data types. Resolves [#84544](https://github.com/ClickHouse/ClickHouse/issues/84544). [#84715](https://github.com/ClickHouse/ClickHouse/pull/84715) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Initialize `DNSResolver` before use to respect custom settings. Fixes [#76296](https://github.com/ClickHouse/ClickHouse/issues/76296). [#81302](https://github.com/ClickHouse/ClickHouse/pull/81302) ([Zhigao Hong](https://github.com/zghong)).
* Fix reading subcolumns from a column with dot in the name in some cases. Resolves [#81261](https://github.com/ClickHouse/ClickHouse/issues/81261), [#82058](https://github.com/ClickHouse/ClickHouse/issues/82058), [#88169](https://github.com/ClickHouse/ClickHouse/issues/88169). [#87205](https://github.com/ClickHouse/ClickHouse/pull/87205) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix GenerateRandom engine crash on non-literal parameters: return BAD\_ARGUMENTS with a clear message instead of LOGICAL\_ERROR. [#88157](https://github.com/ClickHouse/ClickHouse/pull/88157) ([Shafi Ahmed](https://github.com/ita004)).
* Fix removing unused projection columns in the presence of `UNION`. Fixes [#88180](https://github.com/ClickHouse/ClickHouse/issues/88180). [#88350](https://github.com/ClickHouse/ClickHouse/pull/88350) ([Sema Checherinda](https://github.com/CheSema)).
* Fixed incorrect sharding in `JOIN` optimization when the primary key is sorted in descending order. Resolves [#88512](https://github.com/ClickHouse/ClickHouse/issues/88512). [#88794](https://github.com/ClickHouse/ClickHouse/pull/88794) ([Amos Bird](https://github.com/amosbird)).
* Re-enable s3queue\_keeper\_fault\_injection\_probablility, fix issues. [#88800](https://github.com/ClickHouse/ClickHouse/pull/88800) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fixed several issues caused by premature column removal in TTL. Resolves [#88002](https://github.com/ClickHouse/ClickHouse/issues/88002). [#88860](https://github.com/ClickHouse/ClickHouse/pull/88860) ([Amos Bird](https://github.com/amosbird)).
* Throw exception when temporary\_files\_buffer\_size is set to 0. Resolves [#88900](https://github.com/ClickHouse/ClickHouse/issues/88900). [#88917](https://github.com/ClickHouse/ClickHouse/pull/88917) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix `Bad get` error that happened during `Set` index analysis in case the predicate contained `NULL` constant. Fixes [#84856](https://github.com/ClickHouse/ClickHouse/issues/84856) and [#82974](https://github.com/ClickHouse/ClickHouse/issues/82974). [#89429](https://github.com/ClickHouse/ClickHouse/pull/89429) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fix `Cannot add subcolumn X.Y: column with this name already exists`. Resolves [#89599](https://github.com/ClickHouse/ClickHouse/issues/89599). [#89602](https://github.com/ClickHouse/ClickHouse/pull/89602) ([Azat Khuzhin](https://github.com/azat)).
* Fix bugs in the `theilsU` and `contingency` functions that caused incorrect results. [#89760](https://github.com/ClickHouse/ClickHouse/pull/89760) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Fix Alias stability issues: Fix StrictnessLevel with SharedDatabaseCatalog, disallow target is also an alias, and implement additional interfaces (getSerializationHints, supportsReplication, getStoragePolicy, totalBytesUncompressed, lifetimeRows, lifetimeBytes, storesDataOnDisk, tryLockForShare, lockForShare). Resolves [#89106](https://github.com/ClickHouse/ClickHouse/issues/89106). [#89812](https://github.com/ClickHouse/ClickHouse/pull/89812) ([Kai Zhu](https://github.com/nauu)).
* Fix possible crash during remote query with `ARRAY JOIN` inside `IN` and enabled `enable_lazy_columns_replication` setting. Resolves [#90361](https://github.com/ClickHouse/ClickHouse/issues/90361). [#89997](https://github.com/ClickHouse/ClickHouse/pull/89997) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix possible logical error when using `analyzer_compatibility_join_using_top_level_identifier` with multiple joins. [#90010](https://github.com/ClickHouse/ClickHouse/pull/90010) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix inference of bad DateTime64 values from Strings in text formats in some cases. Resolves [#89368](https://github.com/ClickHouse/ClickHouse/issues/89368). [#90013](https://github.com/ClickHouse/ClickHouse/pull/90013) ([Pavel Kruglov](https://github.com/Avogar)).
* Do size checks when deserializing data from aggregation states and other sources. [#90031](https://github.com/ClickHouse/ClickHouse/pull/90031) ([Raúl Marín](https://github.com/Algunenano)).
* Split part ranges by volume characteristics to enable TTL drop merges for cold volumes. After this patch, parts with a max TTL \< now will be removed from cold storage. The algorithm will schedule only **single part drops**. [#90059](https://github.com/ClickHouse/ClickHouse/pull/90059) ([Mikhail Artemenko](https://github.com/Michicosun)).
* In case when Kafka table was created with a setting `kafka_handle_error_mode = 'dead_letter_queue'` and the table `system.dead_letter_queue` is not configured the server may have crashed. This behaviour is fixed. Resolves [#87573](https://github.com/ClickHouse/ClickHouse/issues/87573). [#90064](https://github.com/ClickHouse/ClickHouse/pull/90064) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Fix possible error `Column with Array type is not represented by ColumnArray column: Replicated` during insertion with usage of `ARRAY JOIN` and enabled `enable_lazy_columns_replication` setting. [#90066](https://github.com/ClickHouse/ClickHouse/pull/90066) ([Pavel Kruglov](https://github.com/Avogar)).
* Fixed a crash during the clean server shutdown due to wrong destruction order. Resolves [#82420](https://github.com/ClickHouse/ClickHouse/issues/82420). [#90076](https://github.com/ClickHouse/ClickHouse/pull/90076) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Fix logical error and modulo bug in `numbers` system table when big step size is used. Closes [#83398](https://github.com/ClickHouse/ClickHouse/issues/83398). [#90123](https://github.com/ClickHouse/ClickHouse/pull/90123) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Fix parquet writing not preserving original order when using single threaded writing with the native writer. Partially reverts [https://github.com/ClickHouse/ClickHouse/pull/64424/files](https://github.com/ClickHouse/ClickHouse/pull/64424/files). [#90126](https://github.com/ClickHouse/ClickHouse/pull/90126) ([Arthur Passos](https://github.com/arthurpassos)).
* Do not apply constant node optimization to LIMIT/OFFSET expression. Fixes [#89607](https://github.com/ClickHouse/ClickHouse/issues/89607). [#90156](https://github.com/ClickHouse/ClickHouse/pull/90156) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Fix hive partitioning incompatibility preventing smooth upgrade in 25.8 (fixes error `All hive partitioning columns must be present in the schema` during upgrade). [#90202](https://github.com/ClickHouse/ClickHouse/pull/90202) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix JSON Exception in iceberg table with timestamp column when using glue catalog. Resolves [#90210](https://github.com/ClickHouse/ClickHouse/issues/90210). [#90209](https://github.com/ClickHouse/ClickHouse/pull/90209) ([Alsu Giliazova](https://github.com/alsugiliazova)).
* Fixes a row-count mismatch in MergeTreeReaderIndex when the part's only has fewer rows than index\_granularity. Resolves [#89691](https://github.com/ClickHouse/ClickHouse/issues/89691). [#90254](https://github.com/ClickHouse/ClickHouse/pull/90254) ([Peng Jian](https://github.com/fastio)).
* Fix infinite `nan`/`inf` `WITH FILL` query. Resolves [#69261](https://github.com/ClickHouse/ClickHouse/issues/69261). [#90255](https://github.com/ClickHouse/ClickHouse/pull/90255) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fix 'column not found' error with query\_plan\_use\_logical\_join\_step=0 and residual condition in JOIN ON. Resolves [#88635](https://github.com/ClickHouse/ClickHouse/issues/88635). [#90279](https://github.com/ClickHouse/ClickHouse/pull/90279) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix some queries with aggregated projection optimization. [#90288](https://github.com/ClickHouse/ClickHouse/pull/90288) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Fix bug in reading subcolumns from JSON in compact parts that could lead to `CANNOT_READ_ALL_DATA` error. Resolves [#90264](https://github.com/ClickHouse/ClickHouse/issues/90264). [#90302](https://github.com/ClickHouse/ClickHouse/pull/90302) ([Pavel Kruglov](https://github.com/Avogar)).
* Now ClickHouse will not use read-in-order optimization for iceberg if sort order is not specified manifest files (or not the same) with default\_sort\_order in table. Fixes [#89178](https://github.com/ClickHouse/ClickHouse/issues/89178). [#90304](https://github.com/ClickHouse/ClickHouse/pull/90304) ([alesapin](https://github.com/alesapin)).
* Time and Time64 now should respect timezones correctly while converting from DateTime and DateTime64 (it must show time in the same timezone as it shows for the user as a DateTime\[64]). Closes [#89896](https://github.com/ClickHouse/ClickHouse/issues/89896). [#90310](https://github.com/ClickHouse/ClickHouse/pull/90310) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Fixes a bug where `SELECT CAST(CAST(now(), 'Time'), 'Time64')` was producing incorrect result. Closes [#88349](https://github.com/ClickHouse/ClickHouse/issues/88349). [#90324](https://github.com/ClickHouse/ClickHouse/pull/90324) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Fixed crash on integer overflow in randomStringUTF8. [#90326](https://github.com/ClickHouse/ClickHouse/pull/90326) ([Michael Kolupaev](https://github.com/al13n321)).
* Fixed cluster discovery updates in multicluster setups with `multicluster_root_path` to prevent delays and missing ZooKeeper updates. [#90341](https://github.com/ClickHouse/ClickHouse/pull/90341) ([RinChanNOW](https://github.com/RinChanNOWWW)).
* Fix possible logical error in prewhere on non-existing JSON path with index\_granularity\_bytes=0. Resolves [#86924](https://github.com/ClickHouse/ClickHouse/issues/86924). [#90375](https://github.com/ClickHouse/ClickHouse/pull/90375) ([Pavel Kruglov](https://github.com/Avogar)).
* Fixed a bug in `L2DistanceTransposed` that caused crashes when the precision argument exceeded valid range. Closes [#90401](https://github.com/ClickHouse/ClickHouse/issues/90401). [#90405](https://github.com/ClickHouse/ClickHouse/pull/90405) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Fix possible logical error in `arrayUnion` with `Array(Dynamic)` argument. Resolves [#90270](https://github.com/ClickHouse/ClickHouse/issues/90270). [#90409](https://github.com/ClickHouse/ClickHouse/pull/90409) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix possible logical error during renaming and modifying the same Nested column in one ALTER. Resolves [#90406](https://github.com/ClickHouse/ClickHouse/issues/90406). [#90412](https://github.com/ClickHouse/ClickHouse/pull/90412) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix parsing JSON/Dynamic/Variant values from HTTP parameters. Resolves [#88925](https://github.com/ClickHouse/ClickHouse/issues/88925). [#90430](https://github.com/ClickHouse/ClickHouse/pull/90430) ([Pavel Kruglov](https://github.com/Avogar)).
* Fixed a race condition in Hive partitioning where a static `KeyValuePairExtractor` caused data corruption or crashes during concurrent file reads. [#90474](https://github.com/ClickHouse/ClickHouse/pull/90474) ([Paresh Joshi](https://github.com/pareshjoshij)).
* Fixed incorrect distance calculations in `L2DistanceTransposed` when using array reference vectors (which default to `Array(Float64))` with `QBit` columns of non-`Float64` element types (`Float32`, `BFloat16`). The function now automatically casts the reference vector to match the `QBit`'s element type. Resolves [#89976](https://github.com/ClickHouse/ClickHouse/issues/89976). [#90485](https://github.com/ClickHouse/ClickHouse/pull/90485) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Fixes a bug where `toDateTimeOrNull` of a negative argument returns NULL. [#90490](https://github.com/ClickHouse/ClickHouse/pull/90490) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Fix possible logical error during output of `LowCardinality(Bool/Date32)` in `Arrow` format. Resolves [#83883](https://github.com/ClickHouse/ClickHouse/issues/83883). [#90505](https://github.com/ClickHouse/ClickHouse/pull/90505) ([Pavel Kruglov](https://github.com/Avogar)).
* Fixed IPv4 parsing functions (e.g. `IPv4StringToNumOrDefault`) returning garbage for some invalid inputs. Resolves [#90544](https://github.com/ClickHouse/ClickHouse/issues/90544). Resolves [#87583](https://github.com/ClickHouse/ClickHouse/issues/87583). [#90545](https://github.com/ClickHouse/ClickHouse/pull/90545) ([Michael Kolupaev](https://github.com/al13n321)).
* Retry to markReplicasActive when failing to resolve address during local host check: Print a warning log if there is an exception during self host check in DDLTask. In DDLWorker::markReplicasActive, throw an exception to retry if there is no local host found and there are host IDs in clusters. [#90556](https://github.com/ClickHouse/ClickHouse/pull/90556) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Fix logical error caused by a rare case in `equals` function. Closes [#88142](https://github.com/ClickHouse/ClickHouse/issues/88142). [#90557](https://github.com/ClickHouse/ClickHouse/pull/90557) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Hopefully fixes thread sanitizer crashes in `test_ssh/test.py::test_paramiko_password`. [#90612](https://github.com/ClickHouse/ClickHouse/pull/90612) ([Govind R Nair](https://github.com/Revertionist)).
* Fix logical error in `concatWithSeparator` function when using const non-string column. Closes [#90596](https://github.com/ClickHouse/ClickHouse/issues/90596). [#90655](https://github.com/ClickHouse/ClickHouse/pull/90655) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Fix formatting for `INTO OUTFILE`. Resolves [#90207](https://github.com/ClickHouse/ClickHouse/issues/90207). [#90656](https://github.com/ClickHouse/ClickHouse/pull/90656) ([Azat Khuzhin](https://github.com/azat)).
* Fix potential crash when executing mutations with subqueries and `allow_statistics_optimize=1`. Resolves [#90626](https://github.com/ClickHouse/ClickHouse/issues/90626). [#90664](https://github.com/ClickHouse/ClickHouse/pull/90664) ([Azat Khuzhin](https://github.com/azat)).
* Fixed analyzer validation for `LIMIT BY` with `GROUP BY` to produce correct `NOT_AN_AGGREGATE` error instead of `NOT_FOUND_COLUMN_IN_BLOCK` when `LIMIT BY` uses columns not in `GROUP BY`. Closes [#89713](https://github.com/ClickHouse/ClickHouse/issues/89713). [#90665](https://github.com/ClickHouse/ClickHouse/pull/90665) ([xiaohuanlin](https://github.com/xiaohuanlin)).
* Fix type-casting errors when using `LowCardinality` columns in partition keys. Closes [#89412](https://github.com/ClickHouse/ClickHouse/issues/89412). [#90666](https://github.com/ClickHouse/ClickHouse/pull/90666) ([xiaohuanlin](https://github.com/xiaohuanlin)).
* Fix issue where queries with filter predicates containing constants folded from non-deterministic functions (e.g. `shardNum()`) could incorrectly use query condition cache. [#90692](https://github.com/ClickHouse/ClickHouse/pull/90692) ([Eduard Karacharov](https://github.com/korowa)).
* Fix segfault on query with EXISTS function in join on section. Now query simply returns `INVALID_JOIN_ON_EXPRESSION` error. Close [#90698](https://github.com/ClickHouse/ClickHouse/issues/90698). [#90719](https://github.com/ClickHouse/ClickHouse/pull/90719) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix Logical error: 'Inconsistent AST formatting' for AccessRightsElement when using the default database without any table. [#90742](https://github.com/ClickHouse/ClickHouse/pull/90742) ([Pablo Marcos](https://github.com/pamarcos)).
* Fix access validation for `ALTER UPDATE` queries when a `remote` table function is used with `localhost` as a target host. [#90761](https://github.com/ClickHouse/ClickHouse/pull/90761) ([pufit](https://github.com/pufit)).
* Fix named collections hidden secrets to depend on `display_secrets_in_show_and_select` and `format_display_secrets_in_show_and_select`. [#90765](https://github.com/ClickHouse/ClickHouse/pull/90765) ([Pablo Marcos](https://github.com/pamarcos)).
* Disable `enable_shared_storage_snapshot_in_query` (leads to memory leaks). [#90770](https://github.com/ClickHouse/ClickHouse/pull/90770) ([Azat Khuzhin](https://github.com/azat)).
* Fix duplicate data issue in RIGHT JOIN with distributed table when parallel replicas enabled. [#90806](https://github.com/ClickHouse/ClickHouse/pull/90806) ([zoomxi](https://github.com/zoomxi)).
* Fix possible inconsistent state of shared data and dynamic paths in JSON that could lead to logical errors and unexpected results. [#90816](https://github.com/ClickHouse/ClickHouse/pull/90816) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix ALTER MODIFY QUERY with dictGet() and dictionary name in CSE for SharedCatalog (cloud only feature). [#90860](https://github.com/ClickHouse/ClickHouse/pull/90860) ([Azat Khuzhin](https://github.com/azat)).
* Fix compatibility of in-memory serialization of String aggregation state. Different serialization could lead to duplicate results if aggregation query is executed on instances with different versions. New serialization can be enabled with `serialize_string_in_memory_with_zero_byte`. [#90880](https://github.com/ClickHouse/ClickHouse/pull/90880) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix background flush of Buffer in case of frequent INSERTs. [#90892](https://github.com/ClickHouse/ClickHouse/pull/90892) ([Azat Khuzhin](https://github.com/azat)).
* Don't list contrib/ parent folder in system.licenses. [#90901](https://github.com/ClickHouse/ClickHouse/pull/90901) ([Raúl Marín](https://github.com/Algunenano)).
* Fix high memory usage during reading JSON/Dynamic/Variant columns. [#90907](https://github.com/ClickHouse/ClickHouse/pull/90907) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix buffer allocation for base58Decode function. [#90909](https://github.com/ClickHouse/ClickHouse/pull/90909) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix possible logical error upon receiving another read request from a replica after a response with the `finish=true` flag was sent. This was possible due to a logical race condition within `MergeTreeReadPoolParallelReplicas`, although it was very unlikely to occur. [#90921](https://github.com/ClickHouse/ClickHouse/pull/90921) ([Nikita Taranov](https://github.com/nickitat)).
* Fix wildcard grants check for partial revoke. Added more tests. [#90922](https://github.com/ClickHouse/ClickHouse/pull/90922) ([pufit](https://github.com/pufit)).
* Fixes `SummingMergeTree` aggregation for `Nested` `LowCardinality` columns. [#90927](https://github.com/ClickHouse/ClickHouse/pull/90927) ([Ivan Babrou](https://github.com/bobrik)).
* Fix handling global grants with wildcard revokes Fixes the issue when revoking a wildcard grant can accidentally revoke some global-level grants like `CREATE USER`. [#90928](https://github.com/ClickHouse/ClickHouse/pull/90928) ([pufit](https://github.com/pufit)).
* Fix possible infinite loop in azure list blobs. [#90947](https://github.com/ClickHouse/ClickHouse/pull/90947) ([Julia Kartseva](https://github.com/jkartseva)).
* Fix excessive Buffer flushes (burns CPU and produce tons of logs). [#91000](https://github.com/ClickHouse/ClickHouse/pull/91000) ([Azat Khuzhin](https://github.com/azat)).
* ... Don't allow adaptive\_write\_buffer\_initial\_size set to 0. [#91001](https://github.com/ClickHouse/ClickHouse/pull/91001) ([Pedro Ferreira](https://github.com/PedroTadim)).
* Fix bug in JSON when path can be both in shared data and dynamic paths during sub-object reading in Compact parts with disabled `write_marks_for_substreams_in_compact_parts`. [#91014](https://github.com/ClickHouse/ClickHouse/pull/91014) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix std::out\_of\_range in CTE with dictGet with no arguments. Closes [#91027](https://github.com/ClickHouse/ClickHouse/issues/91027). [#91022](https://github.com/ClickHouse/ClickHouse/pull/91022) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix reading dynamic subcolumns from materialized columns in mutations. Closes [#90653](https://github.com/ClickHouse/ClickHouse/issues/90653). [#91040](https://github.com/ClickHouse/ClickHouse/pull/91040) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix `arrayFilter` function not working when using empty array and `isNull` function. Closes [#73849](https://github.com/ClickHouse/ClickHouse/issues/73849). [#91105](https://github.com/ClickHouse/ClickHouse/pull/91105) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Fix logical error in `ARRAY JOIN` when one of the table columns is empty tuple column. Closes [#90801](https://github.com/ClickHouse/ClickHouse/issues/90801). [#91123](https://github.com/ClickHouse/ClickHouse/pull/91123) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Fix lazy materialization of a column added via alter add column in old parts. [#91142](https://github.com/ClickHouse/ClickHouse/pull/91142) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix merging JSON columns in Summing/Aggregating/Coalescing MergeTree. Previously it could lead to unexpected dynamic paths durign writing to data parts. [#91151](https://github.com/ClickHouse/ClickHouse/pull/91151) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix possible inconsistent dynamic structure during writing in compact parts that could lead to segfault. [#91152](https://github.com/ClickHouse/ClickHouse/pull/91152) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix parsing of subnormal float values in scientific notation. Closes [#78903](https://github.com/ClickHouse/ClickHouse/issues/78903). [#91162](https://github.com/ClickHouse/ClickHouse/pull/91162) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Fix wrong schema inference in INSERT SELECT from a subquery with a source with an implicit schema. [#91204](https://github.com/ClickHouse/ClickHouse/pull/91204) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Fix [https://github.com/clickhouse/clickhouse/issues/91206](https://github.com/clickhouse/clickhouse/issues/91206) when we create a table with statistics and write someting and drop one statistics, it will crash when we read it again. because we assume the serialize and deserialize will have same types statistics. in this fix, we will check if the current metadata contains the serialized statistics, if not, we make a mock statistics and deserialize only to skip it. [#91227](https://github.com/ClickHouse/ClickHouse/pull/91227) ([Han Fei](https://github.com/hanfei1991)).
* Fix inserting into CoalescingMergeTree column with Tuple of JSON/Dynamic and LowCardinality. Closes [#91215](https://github.com/ClickHouse/ClickHouse/issues/91215). [#91270](https://github.com/ClickHouse/ClickHouse/pull/91270) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix SYSTEM DROP FILESYSTEM CACHE ON CLUSTER. [#91304](https://github.com/ClickHouse/ClickHouse/pull/91304) ([Anton Ivashkin](https://github.com/ianton-ru)).
* Fix possible logical error "Bad cast from type DB::ColumnSparse to DB::ColumnNullable". Closes [#91284](https://github.com/ClickHouse/ClickHouse/issues/91284). [#91309](https://github.com/ClickHouse/ClickHouse/pull/91309) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix a crash when maliciously crafted byte streams deserialize into nested QBit types, which should be impossible but could be exploited to crash the server. [#91313](https://github.com/ClickHouse/ClickHouse/pull/91313) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Fix Alias table with empty args in Replicated database. Resolved [#91378](https://github.com/ClickHouse/ClickHouse/issues/91378). [#91382](https://github.com/ClickHouse/ClickHouse/pull/91382) ([Kai Zhu](https://github.com/nauu)).
* Currently, the setting is set to false, so when async insert queue is flushed to a remote server, the inserts are always synchronous. Even in case of the setting is True for a user. [#91386](https://github.com/ClickHouse/ClickHouse/pull/91386) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
* Remove Sparse columns from header in merge algorithms. Closes [#91377](https://github.com/ClickHouse/ClickHouse/issues/91377). [#91396](https://github.com/ClickHouse/ClickHouse/pull/91396) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix hive partitioning bug in 25.8 which can lead to incorrectly thrown exception `A hive partitioned file can't contain only partition columns`. [#91403](https://github.com/ClickHouse/ClickHouse/pull/91403) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix crash in `dictGetDescendants` caused by `NULL` when dictionary type has Hierarchy support but no column is `HIERARCHICAL`. Closes [#92026](https://github.com/ClickHouse/ClickHouse/issues/92026). Closes [#92121](https://github.com/ClickHouse/ClickHouse/issues/92121). [#91420](https://github.com/ClickHouse/ClickHouse/pull/91420) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Fix crash in `IN` function when lambda and non-const tuple arguments are used. Closes [#91379](https://github.com/ClickHouse/ClickHouse/issues/91379). [#91446](https://github.com/ClickHouse/ClickHouse/pull/91446) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Fixed parallel writes triggered by MaterializedView inserts into storages that do not support them. [#91449](https://github.com/ClickHouse/ClickHouse/pull/91449) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Handle null values for Ytsaurus xml dictionaries. [#91465](https://github.com/ClickHouse/ClickHouse/pull/91465) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* Fixed `QBit` type failing with query parameters like `SET param_q=[1,2,3,4]; SELECT {q:QBit(Float32,4)}`. [#91488](https://github.com/ClickHouse/ClickHouse/pull/91488) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Fix LOGICAL\_ERROR when untuple is used in the constant expression. [#91507](https://github.com/ClickHouse/ClickHouse/pull/91507) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Fix possible datarace in `librdkafka`. [#91521](https://github.com/ClickHouse/ClickHouse/pull/91521) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Fix logical error caused by asterisks argument in `remote` function. Closes [#90568](https://github.com/ClickHouse/ClickHouse/issues/90568). [#91524](https://github.com/ClickHouse/ClickHouse/pull/91524) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Fixes an overflow while reading from ORC format for Date and DateTime64 types. Closes [#70976](https://github.com/ClickHouse/ClickHouse/issues/70976). [#91572](https://github.com/ClickHouse/ClickHouse/pull/91572) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Disallow ALTERs for Object Storage table engines. For example, ALTER ADD PROJECTION could have led to an inability to restart the server, since Object Storage engines do not support projections. [#91573](https://github.com/ClickHouse/ClickHouse/pull/91573) ([Nikolay Degterinsky](https://github.com/evillique)).
* Fixed [`L2DistanceTransposed`](/reference/functions/regular-functions/distance-functions#L2DistanceTransposed) returning incorrect results when using non-constant reference vectors (e.g., from a table). [#91517](https://github.com/ClickHouse/ClickHouse/issues/91517). [#91593](https://github.com/ClickHouse/ClickHouse/pull/91593) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Fixes a bug for JOINs on FALSE conditions returning `LOGICAL_ERROR` during a dispatch stage. Closes [#91173](https://github.com/ClickHouse/ClickHouse/issues/91173). [#91598](https://github.com/ClickHouse/ClickHouse/pull/91598) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Fix increased memory usage in join with "additional filter", close [#91011](https://github.com/ClickHouse/ClickHouse/issues/91011). [#91664](https://github.com/ClickHouse/ClickHouse/pull/91664) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fixes JOIN queries with view and enabled parallel replicas. [#91813](https://github.com/ClickHouse/ClickHouse/pull/91813) ([Igor Nikonov](https://github.com/devcrafter)).
* Fix delta lake setting `delta_lake_snapshot_version` which could give incorrect result when used with table engine (not table function) and value -1 (disabled) after snapshot version was used before that. Closes [#87676](https://github.com/ClickHouse/ClickHouse/issues/87676). [#91818](https://github.com/ClickHouse/ClickHouse/pull/91818) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix LOGICAL\_ERROR in RecursiveCTEChunkGenerator. [#91827](https://github.com/ClickHouse/ClickHouse/pull/91827) ([Pablo Marcos](https://github.com/pamarcos)).
* Fix block structure mismatch with queries using FINAL and PREWHERE. [#91847](https://github.com/ClickHouse/ClickHouse/pull/91847) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix logical error with `join_use_nulls` and multiple joins along with cross join. [#91853](https://github.com/ClickHouse/ClickHouse/pull/91853) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Add repair mechanism for JSON with duplicated path in shared data and dynamic paths that could happen because of the bug that was fixed in [https://github.com/ClickHouse/ClickHouse/pull/90816](https://github.com/ClickHouse/ClickHouse/pull/90816). [#91886](https://github.com/ClickHouse/ClickHouse/pull/91886) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix the ORC reader bug when reading string columns that are encoded with DICTIONARY\_V2 and contain only NULL values. [#91889](https://github.com/ClickHouse/ClickHouse/pull/91889) ([Peng Jian](https://github.com/fastio)).
* Fix a serialization inconsistency between sparse and nullable substreams in Tuple columns that could lead to corrupted parts or crashes during reading. This addresses [https://github.com/ClickHouse/ClickHouse/pull/91851](https://github.com/ClickHouse/ClickHouse/pull/91851) . @Algunenano Could you please help check if this can fix the stress test in private repo? @CurtizJ Could you also help take a look please? Thanks!. [#91932](https://github.com/ClickHouse/ClickHouse/pull/91932) ([Amos Bird](https://github.com/amosbird)).
* Fix `Directory '{}' does not exist (LOGICAL_ERROR)` when creating backups on plain-rewritable disks. [#91935](https://github.com/ClickHouse/ClickHouse/pull/91935) ([Julia Kartseva](https://github.com/jkartseva)).
* Prevent crash when connecting to mongodb with named collections. [#91959](https://github.com/ClickHouse/ClickHouse/pull/91959) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix "TOO\_MANY\_MARKS" error which could have happened after some `ALTER` queries for compact parts. [#91980](https://github.com/ClickHouse/ClickHouse/pull/91980) ([alesapin](https://github.com/alesapin)).
* Close [https://github.com/clickhouse/clickhouse/issues/87417](https://github.com/clickhouse/clickhouse/issues/87417) the writing schema of v1 format has a mistake : the type of "added\_snapshot\_id" should be "long" rather than "null, long" because it is required. it is a bug because it's not compatible with other system like spark. when we mixed there manifest files, the bug happens. [#92078](https://github.com/ClickHouse/ClickHouse/pull/92078) ([Han Fei](https://github.com/hanfei1991)).
* Fix the wrong names of `readWKT`, `readWKB`, which were in the wrong style in the previous versions. [#92094](https://github.com/ClickHouse/ClickHouse/pull/92094) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix numerous logical errors, overflow and functional bugs in `midpoint` function. Closes [#91816](https://github.com/ClickHouse/ClickHouse/issues/91816). [#92102](https://github.com/ClickHouse/ClickHouse/pull/92102) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Fixes incorrect results that could appear when reading certain subcolumns (e.g., string size) with sparse encoding. [#92156](https://github.com/ClickHouse/ClickHouse/pull/92156) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix `system.view_refreshes` failing with error `No macro 'replica' in config`. [#92203](https://github.com/ClickHouse/ClickHouse/pull/92203) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix UDF replace in format. [#92210](https://github.com/ClickHouse/ClickHouse/pull/92210) ([Raúl Marín](https://github.com/Algunenano)).
* In `ddlworker::markreplicasactive`, if there is no active host found, and the `remote_servers` has some host\_ids, we print a warning log instead of throwing an exception. [#92223](https://github.com/ClickHouse/ClickHouse/pull/92223) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Surround operators `IN`, `NOT IN` with parentheses. Fixes [#85075](https://github.com/ClickHouse/ClickHouse/issues/85075). [#92225](https://github.com/ClickHouse/ClickHouse/pull/92225) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
* Fix backup of KeeperMap and Memory tables. Creating backup of tables using one of those two engines with `max_compress_block_size` set to `0` could lead to a crash. [#92237](https://github.com/ClickHouse/ClickHouse/pull/92237) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix crash when reading both String data and .size subcolumn from Log engine. This fixes [#89909](https://github.com/ClickHouse/ClickHouse/issues/89909). This contains some commits in [#92290](https://github.com/ClickHouse/ClickHouse/issues/92290). [#92341](https://github.com/ClickHouse/ClickHouse/pull/92341) ([Amos Bird](https://github.com/amosbird)).
* Fix logical error caused by using `Nothing` type in `caseWithExpression` function arguments . Closes [#85354](https://github.com/ClickHouse/ClickHouse/issues/85354). [#92351](https://github.com/ClickHouse/ClickHouse/pull/92351) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Fix possible crash in aggregate functions after MEMORY\_LIMIT\_EXCEEDED. [#92390](https://github.com/ClickHouse/ClickHouse/pull/92390) ([Azat Khuzhin](https://github.com/azat)).
#### Build/Testing/Packaging Improvement
* Use `clang-21` in CI. [#87074](https://github.com/ClickHouse/ClickHouse/pull/87074) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Avoid downloading from cmake when cross-compiling. [#90506](https://github.com/ClickHouse/ClickHouse/pull/90506) ([Raúl Marín](https://github.com/Algunenano)).
ClickHouse release 25.11, 2025-11-27
#### Backward Incompatible Change
* Remove deprecated `Object` type. [#85718](https://github.com/ClickHouse/ClickHouse/pull/85718) ([Pavel Kruglov](https://github.com/Avogar)).
* Remove the obsolete `LIVE VIEW` feature. If you use `LIVE VIEW`, upgrading to the new version will not be possible. [#88706](https://github.com/ClickHouse/ClickHouse/pull/88706) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* In previous versions, the `Geometry` type was aliased to `String`, but now it is a full-featured type. [#83344](https://github.com/ClickHouse/ClickHouse/pull/83344) ([scanhex12](https://github.com/scanhex12)).
* Escape filenames created for `Variant` type subcolumns in Wide data part of MergeTree tables. This change breaks compatibility with old tables with Variant/Dynamic/JSON data types. It fixes storing types with special symbols inside Variant (like DateTime with specific timezone that contains `\`). Escaping can be disabled by changing MergeTree setting `escape_variant_subcolumn_filenames` (to keep compatibility disable this setting in the config for MergeTree or set `compatibility` setting to the previous version before upgrade). Resolves [#69590](https://github.com/ClickHouse/ClickHouse/issues/69590). [#87300](https://github.com/ClickHouse/ClickHouse/pull/87300) ([Pavel Kruglov](https://github.com/Avogar)).
* Enable `with_size_stream` serialization format for the `String` data type by default. This change is backward compatible, but the new serialization format is supported only since version 25.10, which means that downgrading to versions before 25.10 will not be possible. If you want to keep the possibility of downgrading to 25.9 and earlier, configure `serialization_info_version` as `basic` and `string_serialization_version` as `single_stream` in the `merge_tree` section of the server configuration. [#89329](https://github.com/ClickHouse/ClickHouse/pull/89329) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Support exception tagging for HTTP results response to enable clients to parse exceptions more reliably. Resolves [#75175](https://github.com/ClickHouse/ClickHouse/issues/75175). The setting `http_write_exception_in_output_format` is disabled by default for consistency across formats. [#88818](https://github.com/ClickHouse/ClickHouse/pull/88818) ([Kaviraj Kanagaraj](https://github.com/kavirajk)). Although it's not supposed to break any existing behavior (in the worst case, a weird string will be added to exception message), it still makes sense to use "Backward Incompatible Change" as the changelog category just for awareness (because who knows how some trash-scripts may parse the exception message).
* Prohibit the creation of multiple `plain-rewritable` disks on top of the shared object storage path, as this can lead to undefined behavior during collisions of different metadata storage transactions. [#89038](https://github.com/ClickHouse/ClickHouse/pull/89038) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Fixes Kafka storage SASL settings precedence. Table-level SASL settings specified in CREATE TABLE queries now correctly override consumer/producer-specific settings from configuration files. [#89401](https://github.com/ClickHouse/ClickHouse/pull/89401) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Parquet no-timezone timestamps (isAdjustedToUTC=false) are now read as DateTime64(..., 'UTC') instead of DateTime64(...). This is less incorrect as converting such UTC timestamp to string produces a representation of the correct local time. Use `input_format_parquet_local_time_as_utc = 0` to get the old behavior. Resolves [#87469](https://github.com/ClickHouse/ClickHouse/issues/87469). [#87872](https://github.com/ClickHouse/ClickHouse/pull/87872) ([Michael Kolupaev](https://github.com/al13n321)).
* A small improvement for `T64` codec: it no longer accepts data types unaligned with the compression element size, which otherwise triggers a bug. Resolves [#89282](https://github.com/ClickHouse/ClickHouse/issues/89282). [#89432](https://github.com/ClickHouse/ClickHouse/pull/89432) ([yanglongwei](https://github.com/ylw510)).
#### New Feature
* Introduce `Geometry` type. Support reading `WKB` and `WKT` formats for it. In previous versions, the `Geometry` type was aliased to `String`, but now it is a full-featured type. [#83344](https://github.com/ClickHouse/ClickHouse/pull/83344) ([scanhex12](https://github.com/scanhex12)).
* Added new SQL statement `EXECUTE AS` to support user impersonation. Resolves [#39048](https://github.com/ClickHouse/ClickHouse/issues/39048). [#70775](https://github.com/ClickHouse/ClickHouse/pull/70775) ([Shankar](https://github.com/shiyer7474)).
* Add `naiveBayesClassifier` function to classify text using Naive Bayes based on ngrams. [#88677](https://github.com/ClickHouse/ClickHouse/pull/88677) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Add support for fractional `LIMIT` and `OFFSET` for selecting a fraction of a table. Closes [#81892](https://github.com/ClickHouse/ClickHouse/issues/81892). [#88755](https://github.com/ClickHouse/ClickHouse/pull/88755) ([Ahmed Gouda](https://github.com/0xgouda)).
* ClickHouse Subsystem for Microsoft OneLake catalog. [#89366](https://github.com/ClickHouse/ClickHouse/pull/89366) ([scanhex12](https://github.com/scanhex12)).
* Add `flipCoordinates` function that unwraps the required number of dimensions in an array and swaps pointers inside the Tuple column. Resolves [#79469](https://github.com/ClickHouse/ClickHouse/issues/79469). [#79634](https://github.com/ClickHouse/ClickHouse/pull/79634) ([Sachin Kumar Singh](https://github.com/sachinkumarsingh092)).
* Add `system.unicode` table, containing a list of Unicode characters and their properties. Closes [#80055](https://github.com/ClickHouse/ClickHouse/issues/80055). [#80857](https://github.com/ClickHouse/ClickHouse/pull/80857) ([wxybear](https://github.com/wxybear)).
* Add a new MergeTree setting `merge_max_dynamic_subcolumns_in_wide_part` to be able to limit the number of dynamic subcolumns in the Wide part after merge regardless of the parameters specified in the data type. [#87646](https://github.com/ClickHouse/ClickHouse/pull/87646) ([Pavel Kruglov](https://github.com/Avogar)).
* Added support for the `cume_dist` window function. Fixes [#86920](https://github.com/ClickHouse/ClickHouse/issues/86920). [#88102](https://github.com/ClickHouse/ClickHouse/pull/88102) ([Manuel](https://github.com/raimannma)).
* User can now add a new argument `preprocessor` in text index construction. The argument is an arbitrary expression that transforms each document before tokenization. [#88272](https://github.com/ClickHouse/ClickHouse/pull/88272) ([Jimmy Aguilar Mena](https://github.com/Ergus)).
* Adds a `memory_usage` field to `X-ClickHouse-Progress` and `X-ClickHouse-Summary`. This can be used to collect memory usage of queries in real time on the client side. [#88393](https://github.com/ClickHouse/ClickHouse/pull/88393) ([Christoph Wurm](https://github.com/cwurm)).
* Add setting `into_outfile_create_parent_directories` to automatically create parent directories for `INTO OUTFILE`, preventing errors when output paths do not exist. This simplifies workflows where queries write results to nested directories. Resolves [#88610](https://github.com/ClickHouse/ClickHouse/issues/88610). [#88795](https://github.com/ClickHouse/ClickHouse/pull/88795) ([Saksham](https://github.com/Saksham10-11)).
* Support `CREATE OR REPLACE` syntax for temporary tables. Closes [#35888](https://github.com/ClickHouse/ClickHouse/issues/35888). [#89450](https://github.com/ClickHouse/ClickHouse/pull/89450) ([Aleksandr Musorin](https://github.com/AVMusorin)).
* Support for `arrayRemove` to remove all elements equal to `elem` from the array `arr`. Which is only needed for compatibility with Postgres, as ClickHouse already has a way more powerful, `arrayFilter` function. Resolves [#52099](https://github.com/ClickHouse/ClickHouse/issues/52099). [#89585](https://github.com/ClickHouse/ClickHouse/pull/89585) ([tiwarysaurav](https://github.com/tiwarysaurav)).
* Introduces `midpoint` scalar function that calculates average. Resolves [#89029](https://github.com/ClickHouse/ClickHouse/issues/89029). [#89679](https://github.com/ClickHouse/ClickHouse/pull/89679) ([simonmichal](https://github.com/simonmichal)).
* Web UI now provides a download button. It downloads the full result even if the UI displays only part of it. [#89768](https://github.com/ClickHouse/ClickHouse/pull/89768) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add `arrow_flight_request_descriptor_type` setting to support Dremio and other Arrow Flight servers that require command-style descriptors. Implements [#89523](https://github.com/ClickHouse/ClickHouse/issues/89523). [#89826](https://github.com/ClickHouse/ClickHouse/pull/89826) ([Shreyas Ganesh](https://github.com/shreyasganesh0)).
* New aggregate functions `argAndMin` and `argAndMax` that return the argument and the corresponding extreme value. In previous versions it was also possible by using a tuple as an argument. [#89884](https://github.com/ClickHouse/ClickHouse/pull/89884) ([AbdAlRahman Gad](https://github.com/AbdAlRahmanGad)).
* Settings to write and verify parquet checksums. [#79012](https://github.com/ClickHouse/ClickHouse/pull/79012) ([Michael Kolupaev](https://github.com/al13n321)).
* Added `kafka_schema_registry_skip_bytes` setting to Kafka table engine to skip envelope header bytes (e.g., AWS Glue Schema Registry's 19-byte prefix) before parsing message payload. This enables ClickHouse to consume messages from schema registries that add metadata headers. [#89621](https://github.com/ClickHouse/ClickHouse/pull/89621) ([Taras Polishchuk](https://github.com/wake-up-neo)).
* Add `h3PolygonToCells` function which can fill geometry with h3 hexagons. Resolves [#33991](https://github.com/ClickHouse/ClickHouse/issues/33991). [#66262](https://github.com/ClickHouse/ClickHouse/pull/66262) ([Zacharias Knudsen](https://github.com/zachasme)).
* Add new virtual column `_tags` (`Map(String, String)`) with all the tags associated with the blob in S3 (Note, if blob does not have any tags no extra request will be done). Resolves [#72945](https://github.com/ClickHouse/ClickHouse/issues/72945). [#77773](https://github.com/ClickHouse/ClickHouse/pull/77773) ([Zicong Qu](https://github.com/zicongleoqu)).
#### Experimental Feature
* Support TLS certificates retrieval from ACME providers, [RFC 8555](https://datatracker.ietf.org/doc/html/rfc8555), such as Let's Encrypt. This allows the autoconfiguration of TLS on distributed clusters. [#66315](https://github.com/ClickHouse/ClickHouse/pull/66315) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Support part of the Prometheus HTTP Query API. To enable it, add a rule with type `query_api` in the `` section in the configuration file. Supported handlers are `/api/v1/query_range` and `/api/v1/query`. [#86132](https://github.com/ClickHouse/ClickHouse/pull/86132) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Full-text search is now in beta (from a previously experimental stage). [#88928](https://github.com/ClickHouse/ClickHouse/pull/88928) ([Robert Schulze](https://github.com/rschu1ze)).
* Move `Alias` to experimental, can be enabled with `allow_experimental_alias_table_engine = 1`. [#89712](https://github.com/ClickHouse/ClickHouse/pull/89712) ([Kai Zhu](https://github.com/nauu)).
#### Performance Improvement
* Parquet reader v3 is enabled by default. [#88827](https://github.com/ClickHouse/ClickHouse/pull/88827) ([Michael Kolupaev](https://github.com/al13n321)).
* Distributed execution: better split tasks by row groups IDs, not by files. [#87508](https://github.com/ClickHouse/ClickHouse/pull/87508) ([scanhex12](https://github.com/scanhex12)).
* `RIGHT` and `FULL` JOINs now use ConcurrentHashJoin; that means that these types of join are now running with a higher degree of parallelism. Improves various cases for RIGHT and FULL JOINs up to two times. Resolves [#78027](https://github.com/ClickHouse/ClickHouse/issues/78027). [#78462](https://github.com/ClickHouse/ClickHouse/pull/78462) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Optimization for large values of constant expressions in queries. Closes [#72880](https://github.com/ClickHouse/ClickHouse/issues/72880). [#81104](https://github.com/ClickHouse/ClickHouse/pull/81104) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Up to 8x faster `SELECT` queries with heavy partition pruning on tables with 10K+ parts. [#85535](https://github.com/ClickHouse/ClickHouse/pull/85535) ([James Morrison](https://github.com/jawm)).
* When a query uses fixed hash map for aggregation state (group by a small integer), ClickHouse would merge the aggregation state in parallel to speed up the query. [#87366](https://github.com/ClickHouse/ClickHouse/pull/87366) ([Jianfei Hu](https://github.com/incfly)).
* Allow using projections (that use SELECT of `_part_offset` and a different ORDER BY) as a secondary index. When enabled, certain query predicates can be used to read from projection parts and generate bitmaps to filter rows efficiently during the PREWHERE stage. This is the third step to implement projection index, following [#80343](https://github.com/ClickHouse/ClickHouse/issues/80343). [#81021](https://github.com/ClickHouse/ClickHouse/pull/81021) ([Amos Bird](https://github.com/amosbird)).
* Fix VDSO for rare Aarch64 systems and possible other arch/kernel combinations. [#86096](https://github.com/ClickHouse/ClickHouse/pull/86096) ([Tomas Hulata](https://github.com/tombokombo)).
* Improve LZ4 decompression speed by simplifying the code and tweaking the [selection algorithm](https://clickhouse.com/blog/lz4-compression-in-clickhouse#how-to-choose-the-best-algorithm). [#88360](https://github.com/ClickHouse/ClickHouse/pull/88360) ([Raúl Marín](https://github.com/Algunenano)).
* S3 partitions objects internally based on key-name prefixes and automatically scales to high request rates per partition. This change introduces two new BACKUP settings: data\_file\_name\_generator and data\_file\_name\_prefix\_length. When data\_file\_name\_generator=checksum, backup data files are named using a hash of their contents. Example: for a checksum = `abcd1234ef567890abcd1234ef567890` and `data_file_name_prefix_length = 3`, the resulting path will be: `abc/d1234ef567890abcd1234ef567890`. The resulting key distribution enhances load balancing across S3 partitions and reduces the risk of throttling. [#88418](https://github.com/ClickHouse/ClickHouse/pull/88418) ([Julia Kartseva](https://github.com/jkartseva)).
* Improved text index performance by caching dictionary blocks and using hashtables for token lookups instead of binary search. [#88786](https://github.com/ClickHouse/ClickHouse/pull/88786) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Queries can now benefit from `optimize_read_in_order` and `query_plan_optimize_lazy_materialization` simultaneously. Resolves [#88767](https://github.com/ClickHouse/ClickHouse/issues/88767). [#88866](https://github.com/ClickHouse/ClickHouse/pull/88866) ([Manuel](https://github.com/raimannma)).
* Use aggregate projection for queries with `DISTINCT`. Closes [#86925](https://github.com/ClickHouse/ClickHouse/issues/86925). [#88894](https://github.com/ClickHouse/ClickHouse/pull/88894) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Caching posting lists to improve the performance in consecutive runs. [#88912](https://github.com/ClickHouse/ClickHouse/pull/88912) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Run streaming LIMIT BY transform in cases when input sort order matches LIMIT BY keys. [#88969](https://github.com/ClickHouse/ClickHouse/pull/88969) ([Eduard Karacharov](https://github.com/korowa)).
* Allow rewriting `ANY LEFT JOIN` or `ANY RIGHT JOIN` to `ALL INNER JOIN` in some cases. [#89403](https://github.com/ClickHouse/ClickHouse/pull/89403) ([Dmitry Novik](https://github.com/novikd)).
* Reduce the overhead of logging: use less atomic operations per entry. [#89651](https://github.com/ClickHouse/ClickHouse/pull/89651) ([Sergei Trifonov](https://github.com/serxa)).
* When runtime filters are enabled in a query with multiple joins and multiple runtime filters are added, implement the pushdown newly added filter steps over other. [#89725](https://github.com/ClickHouse/ClickHouse/pull/89725) ([Alexander Gololobov](https://github.com/davenger)).
* Slightly speed up some `uniqExact` operations by reducing the overhead of merging hash tables. [#89727](https://github.com/ClickHouse/ClickHouse/pull/89727) ([Raúl Marín](https://github.com/Algunenano)).
* Increase the limit for lazy materialization rows from 10 to 100. [#89772](https://github.com/ClickHouse/ClickHouse/pull/89772) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Enable setting `allow_special_serialization_kinds_in_output_formats` by default. It will lead to less memory usage and improve query speed of output of Sparse/Replicated columns in some row output formats. [#89402](https://github.com/ClickHouse/ClickHouse/pull/89402) ([Pavel Kruglov](https://github.com/Avogar)).
* Added parallelism for `ALTER TABLE ... FREEZE` queries. [#71743](https://github.com/ClickHouse/ClickHouse/pull/71743) ([Kirill](https://github.com/kirillgarbar)).
* Add cache for bcrypt authentication. [#87115](https://github.com/ClickHouse/ClickHouse/pull/87115) ([Nikolay Degterinsky](https://github.com/evillique)).
* If a skip index used in a query with `FINAL` query is on a column that is part of the primary key, the additional step to check for primary key intersection in other parts is unnecessary and now not performed. Resolves [#85897](https://github.com/ClickHouse/ClickHouse/issues/85897). [#88368](https://github.com/ClickHouse/ClickHouse/pull/88368) ([Shankar Iyer](https://github.com/shankar-iyer)).
* The optimization `enable_lazy_columns_replication` is now the default, which will save memory usage in joins. [#89316](https://github.com/ClickHouse/ClickHouse/pull/89316) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Introduce a per-table cache of `ColumnsDescription` for parts, reducing memory usage when tables contain many parts and many columns. [#89352](https://github.com/ClickHouse/ClickHouse/pull/89352) ([Azat Khuzhin](https://github.com/azat)).
* Introduced cache for the deserialized header of the text index to reduce I/O and improve query performance. The cache can be configured via new server settings: - `text_index_header_cache_policy` - `text_index_header_cache_size` - `text_index_header_cache_max_entries` - `text_index_header_cache_size_ratio`. [#89513](https://github.com/ClickHouse/ClickHouse/pull/89513) ([Elmi Ahmadov](https://github.com/ahmadov)).
#### Improvement
* UNION should unify types with `Variant` if needed when `use_variant_as_common_type` is set. Resolves [#82772](https://github.com/ClickHouse/ClickHouse/issues/82772). [#83246](https://github.com/ClickHouse/ClickHouse/pull/83246) ([Mithun p](https://github.com/mithunputhusseri)).
* Roles defined in SQL can now be granted to users defined in `users.xml`. [#88139](https://github.com/ClickHouse/ClickHouse/pull/88139) ([c-end](https://github.com/c-end)).
* Log internal queries (those executed internally by dictionaries, refreshable materialized views, etc) and add the new `is_internal` column to `system.query_log`. [#83277](https://github.com/ClickHouse/ClickHouse/pull/83277) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Enhanced `IS NOT DISTINCT FROM` (`<=>`) operator: added support for inverse `IS DISTINCT FROM`, support compatible numeric operands of different types (e.g., `Nullable(UInt32)` and `Nullable(Int64)`). Resolves [#86763](https://github.com/ClickHouse/ClickHouse/issues/86763). [#87581](https://github.com/ClickHouse/ClickHouse/pull/87581) ([yanglongwei](https://github.com/ylw510)).
* `clickhouse-client` and `clickhouse-local` in the interactive mode will highlight identifiers in the command line that have the same name as the current one under the cursor. [#89689](https://github.com/ClickHouse/ClickHouse/pull/89689) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Output format-related settings now don't affect query caching. Also, the query caching will ignore the `http_response_headers` setting. This is needed to allow implementation of features such as downloading the result from the cache in the Web UI. [#89756](https://github.com/ClickHouse/ClickHouse/pull/89756) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* The HTTP interface will provide `Age` and `Expires` headers when the query result cache is used. The presence of the `Age` header tells whether the result is from the cache, while `Expires` is also set at the first write. Introduce new profile events: `QueryCacheAgeSeconds`, `QueryCacheReadRows`, `QueryCacheReadBytes`, `QueryCacheWrittenRows`, `QueryCacheWrittenBytes`. [#89759](https://github.com/ClickHouse/ClickHouse/pull/89759) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Allow inserting into remote and data lake tables when `disable_insertion_and_mutation` is enabled (which means - read only warehouses in ClickHouse Cloud). [#88549](https://github.com/ClickHouse/ClickHouse/pull/88549) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Add query `SYSTEM DROP TEXT INDEX CACHES`. [#90287](https://github.com/ClickHouse/ClickHouse/pull/90287) ([Anton Popov](https://github.com/CurtizJ)).
* Enable `enable_shared_storage_snapshot_in_query` by default for better consistency guarantees. There should be no downsides. [#82634](https://github.com/ClickHouse/ClickHouse/pull/82634) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Added `send_profile_events` setting which allows clients to reduce network traffic when profile events are unused. [#89588](https://github.com/ClickHouse/ClickHouse/pull/89588) ([Kaviraj Kanagaraj](https://github.com/kavirajk)).
* Allow disabling background download of nearby segments on a per query basis. Fixes [#89524](https://github.com/ClickHouse/ClickHouse/issues/89524). [#89668](https://github.com/ClickHouse/ClickHouse/pull/89668) ([tanner-bruce](https://github.com/tanner-bruce)).
* Allow `FETCH PARTITION` when there are broken disks in replicated merge tree tables. [#58663](https://github.com/ClickHouse/ClickHouse/pull/58663) ([Duc Canh Le](https://github.com/canhld94)).
* Fix uncaught exception while getting MySQL table schema in MySQL database engine. [#69358](https://github.com/ClickHouse/ClickHouse/pull/69358) ([Duc Canh Le](https://github.com/canhld94)).
* All DDL `ON CLUSTER` queries now execute with the original query user context for better access validation. [#71334](https://github.com/ClickHouse/ClickHouse/pull/71334) ([pufit](https://github.com/pufit)).
* Added support for `UUID` in `Parquet` when it is represented by `FixedString(16)` with the logical type `UUID`. [#74484](https://github.com/ClickHouse/ClickHouse/pull/74484) ([alekseev-maksim](https://github.com/alekseev-maksim)).
* Disable ThreadFuzzer in non-server binaries by default. [#89115](https://github.com/ClickHouse/ClickHouse/pull/89115) ([Raúl Marín](https://github.com/Algunenano)).
* Make query plan optimizations visible to the correlated subquery input subplan by postponing it's materialization. Part of [#79890](https://github.com/ClickHouse/ClickHouse/issues/79890). [#85455](https://github.com/ClickHouse/ClickHouse/pull/85455) ([Dmitry Novik](https://github.com/novikd)).
* You can see a progress bar, logs and performance statistics for `CREATE OR REPLACE TABLE` queries with `SELECT` in clickhouse-client. This query will no longer lead to timeout even if the `SELECT` is quite time consuming. Resolves [#38416](https://github.com/ClickHouse/ClickHouse/issues/38416). [#87247](https://github.com/ClickHouse/ClickHouse/pull/87247) ([Diskein](https://github.com/Diskein)).
* Support `JSON` and `Dynamic` types in hash functions. Resolves [#87734](https://github.com/ClickHouse/ClickHouse/issues/87734). [#87791](https://github.com/ClickHouse/ClickHouse/pull/87791) ([Pavel Kruglov](https://github.com/Avogar)).
* Implement missing parts of the ArrowFlight server. [#88013](https://github.com/ClickHouse/ClickHouse/pull/88013) ([Vitaly Baranov](https://github.com/vitlibar)).
* Add multiple histogram metrics for the server and the keeper to instrument the durations of the keeper request execution stages. The following metrics will be added to the server: `keeper_client_queue_duration_milliseconds`, `keeper_client_send_duration_milliseconds`, `keeper_client_roundtrip_duration_milliseconds`. The following metrics will be added to the keeper: `keeper_server_preprocess_request_duration_milliseconds`, `keeper_server_process_request_duration_milliseconds`, `keeper_server_queue_duration_milliseconds`, `keeper_server_send_duration_milliseconds`. [#88158](https://github.com/ClickHouse/ClickHouse/pull/88158) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Add `input_headers` option to `EXPLAIN` query to add input headers to steps. [#88311](https://github.com/ClickHouse/ClickHouse/pull/88311) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Adds profile events to count the number of S3 and AzureBlobStorage requests delayed by throttlers. Fixes the inconsistency of disk-related and non-disk-related ThrottlerCount profile events. Now AzureBlobStorage HTTP DELETE requests are not throttled. [#88535](https://github.com/ClickHouse/ClickHouse/pull/88535) ([Sergei Trifonov](https://github.com/serxa)).
* Cache table-level statistics, add two settings: merge tree setting `refresh_statistics_interval` means the interval of refreshing statistics cache, 0 means no cache will be created. Session setting `use_statistics_cache` means whether to use table-level statistics in a query. Sometimes we want better statistics so we choose to ignore it. [#88670](https://github.com/ClickHouse/ClickHouse/pull/88670) ([Han Fei](https://github.com/hanfei1991)).
* Fixed binary deserialization of `Array` and `Map` to use the `max_binary_array_size` setting instead of `max_binary_string_size` when validating size limits. This ensures that the proper limits are applied when reading in `RowBinary` format. [#88744](https://github.com/ClickHouse/ClickHouse/pull/88744) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Introduced a `LockGuardWithStopWatch` class and used it in the background pool for executing merges. In case a mutex was held for a second or some thread was struggling to get it within a second a warning message will be printed. Moved the heavy code from the destructor of `MergeMutateSelectedEntry` to `finalize` method to avoid holding the lock in `MergeTreeBackground` executor for too long. [#88898](https://github.com/ClickHouse/ClickHouse/pull/88898) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Allow using opt-in AWS regions for S3 automatically when the region is not specified in the endpoint. Reference: [opt-in AWS regions](https://docs.aws.amazon.com/global-infrastructure/latest/regions/aws-regions.html). [#88930](https://github.com/ClickHouse/ClickHouse/pull/88930) ([Andrey Zvonov](https://github.com/zvonand)).
* User can now cancel the query in clickhouse-client by pressing Ctrl-C when the pager is running. Resolves [#80778](https://github.com/ClickHouse/ClickHouse/issues/80778). [#88935](https://github.com/ClickHouse/ClickHouse/pull/88935) ([Grigorii](https://github.com/GSokol)).
* Web UI will display bars in the table even when the values are negative. So it can display a double-sided bar chart with different colors of bars on the negative and positive sides. [#89016](https://github.com/ClickHouse/ClickHouse/pull/89016) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Disable `shared_merge_tree_create_per_replica_metadata_nodes` to reduce the amount of metadata `SharedMergeTree` stores in Keeper. [#89036](https://github.com/ClickHouse/ClickHouse/pull/89036) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Make `S3Queue` respect `disable_insertion_and_mutation` server setting. [#89048](https://github.com/ClickHouse/ClickHouse/pull/89048) ([Raúl Marín](https://github.com/Algunenano)).
* Set default `s3_retry_attempts` to 500 for 25.6 to make sure backups succeed when there's an S3 repartitioning and S3 responds with slow-down errors for more than 10 minutes. [#89051](https://github.com/ClickHouse/ClickHouse/pull/89051) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* The `kafka_compression_codec` and `kafka_compression_level` settings can now be used to specify the compression for Kafka producers in both Kafka engines. [#89073](https://github.com/ClickHouse/ClickHouse/pull/89073) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Add a new column `statistics` in `system.columns`, indicating the types of statistics built on this table. If a type of statistics is automatically created, it will show as (auto) in the suffix. [#89086](https://github.com/ClickHouse/ClickHouse/pull/89086) ([Han Fei](https://github.com/hanfei1991)).
* Improve error message when generic expansion is passed instead of cluster name to a `*Cluster` table function. [#89093](https://github.com/ClickHouse/ClickHouse/pull/89093) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* YTsaurus: allow using a replicated\_table as a data source. [#89107](https://github.com/ClickHouse/ClickHouse/pull/89107) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* Queries starting with whitespace are no longer saved to history in CLI. [#89116](https://github.com/ClickHouse/ClickHouse/pull/89116) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Support Array of String as an input to the `hasAnyTokens` or `hasAllTokens` functions. [#89124](https://github.com/ClickHouse/ClickHouse/pull/89124) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Modify how plain-rewritable disks store their metadata in memory, resolving numerous bugs related to directory nesting and around that. [#89125](https://github.com/ClickHouse/ClickHouse/pull/89125) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Subqueries which take part inside IN expressions when querying Iceberg table will be precomputed in the right way before partition pruning analysis. [#89177](https://github.com/ClickHouse/ClickHouse/pull/89177) ([Daniil Ivanik](https://github.com/divanik)).
* Enable `create_table_empty_primary_key_by_default` by default. This is better for usability. [#89333](https://github.com/ClickHouse/ClickHouse/pull/89333) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix incorrect code in the `Backup` database engine when it can generate an invalid query with `SHOW CREATE DATABASE` or when querying `engine_full` from `system.databases`. Closes [#89477](https://github.com/ClickHouse/ClickHouse/issues/89477). [#89341](https://github.com/ClickHouse/ClickHouse/pull/89341) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* In previous versions, the setting `create_table_empty_primary_key_by_default` was ineffective when you didn't specify the table engine in the CREATE TABLE query. [#89342](https://github.com/ClickHouse/ClickHouse/pull/89342) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Update `chdig` to v25.11.1 - includes major improvements to logging and various other enhancements ([release notes for 25.11](https://github.com/azat/chdig/releases/tag/v25.11.1)). [#89957](https://github.com/ClickHouse/ClickHouse/pull/89957) ([Azat Khuzhin](https://github.com/azat)). ([release notes for 25.10](https://github.com/azat/chdig/releases/tag/v25.10.1)). [#89452](https://github.com/ClickHouse/ClickHouse/pull/89452) ([Azat Khuzhin](https://github.com/azat)).
* Make the resizer of the query textarea in the Web UI full-width, which makes it a little bit more convenient. Also, the browser-native resizer was not available on Safari on iPad, and after this change, you can at least drag the bottom of the textarea if you know. [#89457](https://github.com/ClickHouse/ClickHouse/pull/89457) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Improved memory tracking in hash joins result generation. Previously, temporary allocations during generating join result were not properly tracked, which could lead to memory limit overruns. [#89560](https://github.com/ClickHouse/ClickHouse/pull/89560) ([Azat Khuzhin](https://github.com/azat)).
* Async server log: Flush earlier and increase default queue size. [#89597](https://github.com/ClickHouse/ClickHouse/pull/89597) ([Raúl Marín](https://github.com/Algunenano)).
* Fix wrong `FilesystemCacheBytes` (and others) in `system.asynchronous_metrics`. Run `SYSTEM` queries on filesystem caches only once. Atomic view for caches that points to the same path in `system.filesystem_caches`. [#89640](https://github.com/ClickHouse/ClickHouse/pull/89640) ([Azat Khuzhin](https://github.com/azat)).
* Clarified description of some columns in `system.view_refreshes`. [#89701](https://github.com/ClickHouse/ClickHouse/pull/89701) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Cache S3 credentials interacting with STS endpoint so they can be reused for different function calls. Amount of cached credentials can be controlled with `s3_credentials_provider_max_cache_size`. [#89734](https://github.com/ClickHouse/ClickHouse/pull/89734) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix runtime filter pushdown when there are multiple expression steps below it. [#89741](https://github.com/ClickHouse/ClickHouse/pull/89741) ([Alexander Gololobov](https://github.com/davenger)).
* If the system memory is lower than 5GB, don't mlock the executable by default. [#89751](https://github.com/ClickHouse/ClickHouse/pull/89751) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Type hints in the Web UI no longer overflow into the table header. Also corrected the tooltips display - they are no longer behind the table header. [#89753](https://github.com/ClickHouse/ClickHouse/pull/89753) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Show table properties in Web UI. Clicking on the number of rows or bytes will bring up a query from `system.tables`. Clicking on the table engine will bring up `SHOW TABLES`. [#89771](https://github.com/ClickHouse/ClickHouse/pull/89771) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Support `non_replicated_deduplication_window` for tables with a disk that does not implement writing with append. Resolves [#87281](https://github.com/ClickHouse/ClickHouse/issues/87281). [#89796](https://github.com/ClickHouse/ClickHouse/pull/89796) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Added a possibility to set a list of tables to flush in command `SYSTEM FLUSH ASYNC INSERT QUEUE`. [#89915](https://github.com/ClickHouse/ClickHouse/pull/89915) ([Sema Checherinda](https://github.com/CheSema)).
* Store deduplication blocks ids in the `system.part_log`. [#89928](https://github.com/ClickHouse/ClickHouse/pull/89928) ([Sema Checherinda](https://github.com/CheSema)).
* Changed default of filesystem cache setting `keep_free_space_remove_batch` from 10 to 100, because it is more optimal. [#90030](https://github.com/ClickHouse/ClickHouse/pull/90030) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Introduce the TTL DROP merge type, and do not update the next delete TTL merge schedule after this kind of merges. [#90077](https://github.com/ClickHouse/ClickHouse/pull/90077) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Use lower node limit for RemoveRecursive Keeper request during S3Queue cleanup. [#90201](https://github.com/ClickHouse/ClickHouse/pull/90201) ([Antonio Andelic](https://github.com/antonio2368)).
* Make `SYSTEM FLUSH LOGS` query wait for table creation even when the logs are empty. [#89408](https://github.com/ClickHouse/ClickHouse/pull/89408) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Fix incorrect `rows_before_limit_at_least` when there are multiple remote shards involved in a distributed merging aggregation, or there are subqueries INs. This fixes [#63280](https://github.com/ClickHouse/ClickHouse/issues/63280). [#63511](https://github.com/ClickHouse/ClickHouse/pull/63511) ([Amos Bird](https://github.com/amosbird)).
* Fixed `0 rows in set` appearance after `INSERT INTO ... SELECT` query. Closes [#47800](https://github.com/ClickHouse/ClickHouse/issues/47800). [#79462](https://github.com/ClickHouse/ClickHouse/pull/79462) ([Engel Danila](https://github.com/aaaengel)).
#### Bug Fix (user-visible misbehavior in an official stable release)
* Fix `multiIf` with constant arguments and short-circuit evaluation. Closes [#72714](https://github.com/ClickHouse/ClickHouse/issues/72714). [#84546](https://github.com/ClickHouse/ClickHouse/pull/84546) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Fix logical error when selecting from a table with a subquery constraint. Resolves [#84190](https://github.com/ClickHouse/ClickHouse/issues/84190). [#85575](https://github.com/ClickHouse/ClickHouse/pull/85575) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Fixed a bug for special queries using a URI with question marks. [#85663](https://github.com/ClickHouse/ClickHouse/pull/85663) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Fixed sometimes missing columns in `EXPLAIN indexes = 1` output. Resolves [#86696](https://github.com/ClickHouse/ClickHouse/issues/86696). [#87083](https://github.com/ClickHouse/ClickHouse/pull/87083) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix possible error Cannot add subcolumn with parallel replicas. Closes [#84888](https://github.com/ClickHouse/ClickHouse/issues/84888). [#87514](https://github.com/ClickHouse/ClickHouse/pull/87514) ([Pavel Kruglov](https://github.com/Avogar)).
* In parquet writer, emit `created_by` string in correct format, e.g. `ClickHouse version 25.10.1 (build 5b1dfb14925db8901a4e9202cd5d63c11ecfbb9f)` instead of `ClickHouse v25.9.1.1-testing`. Fix parquet reader compatibility with bad files written by old parquet-mr. [#87735](https://github.com/ClickHouse/ClickHouse/pull/87735) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix phi-squared computation causing incorrect results in `cramersV`, `cramersVBiasCorrected`, `theilsU`, and `contingency`. [#87831](https://github.com/ClickHouse/ClickHouse/pull/87831) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Fix reading mixed array of Floats and Bools in JSON. Previously inserting such data led to an exception. [#88008](https://github.com/ClickHouse/ClickHouse/pull/88008) ([Pavel Kruglov](https://github.com/Avogar)).
* Using shared\_ptr for QueryState in TCPHandler to detect if the state is invalid in setProgressCallback, setFileProgressCallback and setBlockMarshallingCallback. [#88201](https://github.com/ClickHouse/ClickHouse/pull/88201) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Fix logical error in cross join reordering when query\_plan\_optimize\_join\_order\_limit > 1, Close [#89409](https://github.com/ClickHouse/ClickHouse/issues/89409). [#88286](https://github.com/ClickHouse/ClickHouse/pull/88286) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix [#88426](https://github.com/ClickHouse/ClickHouse/issues/88426) 1. Disallow explicit column definitions in Alias and columns are automatically load from the target table. This ensures that the alias always matches the target table's schema. 2. Proxy more methods from the IStorage. [#88552](https://github.com/ClickHouse/ClickHouse/pull/88552) ([Kai Zhu](https://github.com/nauu)).
* After recovering, a Replicated database replica might get stuck for a long time printing messages like `Failed to marked query-0004647339 as finished (finished=No node, synced=No node)`, it's fixed. [#88671](https://github.com/ClickHouse/ClickHouse/pull/88671) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Fix possible "Context has expired" with new analyzer with subqueries. [#88694](https://github.com/ClickHouse/ClickHouse/pull/88694) ([Azat Khuzhin](https://github.com/azat)).
* Fixed a segmentation fault in the Parquet reader when input\_format\_parquet\_local\_file\_min\_bytes\_for\_seek is set to 0. Resolves [#78456](https://github.com/ClickHouse/ClickHouse/issues/78456). [#88784](https://github.com/ClickHouse/ClickHouse/pull/88784) ([Animesh](https://github.com/anibilthare)).
* Fix incorrect min(PK)/max(PK) result when PK is in reverse order. This fixes [#83619](https://github.com/ClickHouse/ClickHouse/issues/83619). [#88796](https://github.com/ClickHouse/ClickHouse/pull/88796) ([Amos Bird](https://github.com/amosbird)).
* Fix propagation of size restrictions by settings max\_table\_size\_to\_drop and max\_partition\_size\_to\_drop on DROP of inner tables. [#88812](https://github.com/ClickHouse/ClickHouse/pull/88812) ([Nikolay Degterinsky](https://github.com/evillique)).
* Fix `top_k` to respect the threshold parameter when called with a single argument. Closes [#88757](https://github.com/ClickHouse/ClickHouse/issues/88757). [#88867](https://github.com/ClickHouse/ClickHouse/pull/88867) ([Manuel](https://github.com/raimannma)).
* ArrowFlight endpoint sources that required an SSL connection (such as behind an AWS ALB) can now properly request a specific dataset. [#88868](https://github.com/ClickHouse/ClickHouse/pull/88868) ([alex-shchetkov](https://github.com/alex-shchetkov)).
* Fix handling of non materialized Nested(Tuple(...)) (added via ALTER). Fixes [#83133](https://github.com/ClickHouse/ClickHouse/issues/83133). [#88879](https://github.com/ClickHouse/ClickHouse/pull/88879) ([Azat Khuzhin](https://github.com/azat)).
* Fix bug in the function `reverseUTF8`. In previous versions, it mistakenly reversed the bytes of UTF-8 code points of length 4. This closes [#88913](https://github.com/ClickHouse/ClickHouse/issues/88913). [#88914](https://github.com/ClickHouse/ClickHouse/pull/88914) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix icebergS3Cluster protocol. Started supporting schema evolution, positional and equality deletes in iceberg cluster function. Resolves [#88287](https://github.com/ClickHouse/ClickHouse/issues/88287). [#88919](https://github.com/ClickHouse/ClickHouse/pull/88919) ([Yang Jiang](https://github.com/Ted-Jiang)).
* Disable parallel\_replicas\_support\_projection for queries with parallel replicas over distributed tables. Closes [#88899](https://github.com/ClickHouse/ClickHouse/issues/88899). [#88922](https://github.com/ClickHouse/ClickHouse/pull/88922) ([zoomxi](https://github.com/zoomxi)).
* Propagate context on internal casts. Fixing multiple issues where cast-settings weren't propagated. Closes [#88873](https://github.com/ClickHouse/ClickHouse/issues/88873). Closes [#78025](https://github.com/ClickHouse/ClickHouse/issues/78025). [#88929](https://github.com/ClickHouse/ClickHouse/pull/88929) ([Manuel](https://github.com/raimannma)).
* Fix getting file format from globs in file() function. Resolves [#88920](https://github.com/ClickHouse/ClickHouse/issues/88920). [#88947](https://github.com/ClickHouse/ClickHouse/pull/88947) ([Vitaly Baranov](https://github.com/vitlibar)).
* Do not check access `SET DEFINER :definer` when creating a view with SQL SECURITY DEFINER. [#88968](https://github.com/ClickHouse/ClickHouse/pull/88968) ([pufit](https://github.com/pufit)).
* Fixed `LOGICAL_ERROR` in `L2DistanceTransposed(vec1, vec2, p)` where the optimisation for partial `QBit` reading incorrectly removed `Nullable` from the return type when `p` was `Nullable`. [#88974](https://github.com/ClickHouse/ClickHouse/pull/88974) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Fix crash in unknown catalog type. Resolves [#88819](https://github.com/ClickHouse/ClickHouse/issues/88819). [#88987](https://github.com/ClickHouse/ClickHouse/pull/88987) ([scanhex12](https://github.com/scanhex12)).
* This closes [#88081](https://github.com/ClickHouse/ClickHouse/issues/88081). [#88988](https://github.com/ClickHouse/ClickHouse/pull/88988) ([scanhex12](https://github.com/scanhex12)).
* Fixed performance degradation in analysis of skipping indexes. [#89004](https://github.com/ClickHouse/ClickHouse/pull/89004) ([Anton Popov](https://github.com/CurtizJ)).
* Fix ACCESS\_ENTITY\_NOT\_FOUND error when trying to execute clusterAllReplicas from a user with a non-existing role. Resolves [#87670](https://github.com/ClickHouse/ClickHouse/issues/87670). [#89068](https://github.com/ClickHouse/ClickHouse/pull/89068) ([pufit](https://github.com/pufit)).
* Fix sparse columns processing by CHECK constraint. Closes [#88637](https://github.com/ClickHouse/ClickHouse/issues/88637). [#89076](https://github.com/ClickHouse/ClickHouse/pull/89076) ([Eduard Karacharov](https://github.com/korowa)).
* Fixed incorrect row count when filling virtual columns in MergeTreeReaderTextIndex causing a crash with LOGICAL\_ERROR. [#89095](https://github.com/ClickHouse/ClickHouse/pull/89095) ([Peng Jian](https://github.com/fastio)).
* Prevent TTL merge counter leaks when exceptions occur during merge preparation. Resolves [#89019](https://github.com/ClickHouse/ClickHouse/issues/89019). [#89127](https://github.com/ClickHouse/ClickHouse/pull/89127) ([save-my-heart](https://github.com/save-my-heart)).
* Fix calculation of buffer size needed for base32/base58 encoding and decoding operations. [#89133](https://github.com/ClickHouse/ClickHouse/pull/89133) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix use-after-free in Distributed due to race between shutdown and background INSERTs. Resolves [#88640](https://github.com/ClickHouse/ClickHouse/issues/88640). [#89136](https://github.com/ClickHouse/ClickHouse/pull/89136) ([Azat Khuzhin](https://github.com/azat)).
* Avoid possible data-races due to mutable exceptions while parsing Parquet. Fixes [#88385](https://github.com/ClickHouse/ClickHouse/issues/88385). [#89174](https://github.com/ClickHouse/ClickHouse/pull/89174) ([Azat Khuzhin](https://github.com/azat)).
* Refreshable materialized view: fixed rare server crash if source table was fully dropped during a refresh. [#89203](https://github.com/ClickHouse/ClickHouse/pull/89203) ([Michael Kolupaev](https://github.com/al13n321)).
* Flush buffers when sending an error in the middle of compressed stream in HTTP interface. [#89256](https://github.com/ClickHouse/ClickHouse/pull/89256) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Prevent query masking rules from being incorrectly applied to DDL statements. [#89272](https://github.com/ClickHouse/ClickHouse/pull/89272) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* Fixed incorrect row count when filling virtual columns in MergeTreeReaderTextIndex causing a crash with LOGICAL\_ERROR. Reopens [#89095](https://github.com/ClickHouse/ClickHouse/issues/89095). [#89303](https://github.com/ClickHouse/ClickHouse/pull/89303) ([Jimmy Aguilar Mena](https://github.com/Ergus)).
* Fix Statistics countmin does not support estimate data type of LowCardinality(Nullable(String)) LOGICAL\_ERROR. [#89343](https://github.com/ClickHouse/ClickHouse/pull/89343) ([Han Fei](https://github.com/hanfei1991)).
* Possible crash/undefined behavior in IN function where primary key column types are different from IN function right side column types. Example: SELECT string\_column, int\_column FROM test\_table WHERE (string\_column, int\_column) IN (SELECT '5', 'not a number'). Appears if many rows are selected and there are rows contain not compatible types. [#89367](https://github.com/ClickHouse/ClickHouse/pull/89367) ([Ilya Golshtein](https://github.com/ilejn)).
* Fix truncating arguments of `countIf(*)`. Closes [#89372](https://github.com/ClickHouse/ClickHouse/issues/89372). [#89373](https://github.com/ClickHouse/ClickHouse/pull/89373) ([Manuel](https://github.com/raimannma)).
* Avoid losing uncompressed checksums for statistics on mutations. [#89381](https://github.com/ClickHouse/ClickHouse/pull/89381) ([Azat Khuzhin](https://github.com/azat)).
* Fix LOGICAL\_ERROR in L2DistanceTransposed(vec1, vec2, p) where the optimization for partial QBit reading incorrectly removed Nullable from the return type when p was LowCardinality(Nullable(T)). Resolves [#88362](https://github.com/ClickHouse/ClickHouse/issues/88362). [#89397](https://github.com/ClickHouse/ClickHouse/pull/89397) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Fix loading tables with incorrect sparse serialization for tuple itself (that is written by older ClickHouse versions). [#89405](https://github.com/ClickHouse/ClickHouse/pull/89405) ([Azat Khuzhin](https://github.com/azat)).
* Fixed incorrect merge handling of TTL-emptied parts with non-empty projections when using `deduplicate_merge_projection_mode='ignore'`. Resolves [#89430](https://github.com/ClickHouse/ClickHouse/issues/89430). [#89458](https://github.com/ClickHouse/ClickHouse/pull/89458) ([Amos Bird](https://github.com/amosbird)).
* Fix logical error in full\_sorting\_merge join with duplicate columns. Resolves [#86957](https://github.com/ClickHouse/ClickHouse/issues/86957). [#89495](https://github.com/ClickHouse/ClickHouse/pull/89495) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix reading of changelogs during Keeper startup in cases a changelog was not renamed properly during rotation. [#89496](https://github.com/ClickHouse/ClickHouse/pull/89496) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix incorrect JOIN results when using OR conditions with unique right table keys. Resolves [#89391](https://github.com/ClickHouse/ClickHouse/issues/89391). [#89512](https://github.com/ClickHouse/ClickHouse/pull/89512) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix possible "Context has expired" with analyzer and PK IN (subquery) (v2). Fixes [#89433](https://github.com/ClickHouse/ClickHouse/issues/89433). [#89527](https://github.com/ClickHouse/ClickHouse/pull/89527) ([Azat Khuzhin](https://github.com/azat)).
* Fix MaterializedPostgreSQL replication for tables with configured uppercase column names. Resolves [#72363](https://github.com/ClickHouse/ClickHouse/issues/72363). [#89530](https://github.com/ClickHouse/ClickHouse/pull/89530) ([Danylo Osipchuk](https://github.com/Lenivaya)).
* Fix a crash in case if a state of an aggregate function contains a serialized value of a column of LowCardinality(String). [#89550](https://github.com/ClickHouse/ClickHouse/pull/89550) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix crash when using `ARRAY JOIN` on the right side of a JOIN with `enable_lazy_columns_replication` setting enabled. [#89551](https://github.com/ClickHouse/ClickHouse/pull/89551) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix logical error with query\_plan\_convert\_join\_to\_in. Resolves [#89066](https://github.com/ClickHouse/ClickHouse/issues/89066). [#89554](https://github.com/ClickHouse/ClickHouse/pull/89554) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fixed exception in statistics estimator when trying to estimate conditions with mismatched column and constant types that cannot be converted. [#89596](https://github.com/ClickHouse/ClickHouse/pull/89596) ([Han Fei](https://github.com/hanfei1991)).
* Add runtime filters only for supported join algorithms i.e. hash joins. A filter can only be built when join algorithm first fully reads the right side and then reads the left side, but FullSortingMergeJoin for example reads both sides simultaneously. Fixes [#89220](https://github.com/ClickHouse/ClickHouse/issues/89220). [#89652](https://github.com/ClickHouse/ClickHouse/pull/89652) ([Alexander Gololobov](https://github.com/davenger)).
* Fix `hasAnyTokens`, `hasAllTokens` and `tokens` functions concurrent executions with the `sparseGrams` tokenizer. Resolves [#89605](https://github.com/ClickHouse/ClickHouse/issues/89605). [#89665](https://github.com/ClickHouse/ClickHouse/pull/89665) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Fix logical error/crash with join runtime filter in some cases. Fixes [#89062](https://github.com/ClickHouse/ClickHouse/issues/89062). [#89666](https://github.com/ClickHouse/ClickHouse/pull/89666) ([Alexander Gololobov](https://github.com/davenger)).
* Fix possible logical error during ARRAY JOIN on Map column with enabled `enable_lazy_columns_replication`. Closes [#89705](https://github.com/ClickHouse/ClickHouse/issues/89705). [#89717](https://github.com/ClickHouse/ClickHouse/pull/89717) ([Pavel Kruglov](https://github.com/Avogar)).
* Avoid crash due to reading from remote server after disconnect in remote queries during cancellation. Resolves [#89468](https://github.com/ClickHouse/ClickHouse/issues/89468). [#89740](https://github.com/ClickHouse/ClickHouse/pull/89740) ([Azat Khuzhin](https://github.com/azat)).
* Fix race condition in projection index reading path. Resolves [#89497](https://github.com/ClickHouse/ClickHouse/issues/89497). [#89762](https://github.com/ClickHouse/ClickHouse/pull/89762) ([Peng Jian](https://github.com/fastio)).
* Fix bug in projection index reading that could cause race conditions. Resolves [#89497](https://github.com/ClickHouse/ClickHouse/issues/89497). [#89775](https://github.com/ClickHouse/ClickHouse/pull/89775) ([Amos Bird](https://github.com/amosbird)).
* Fixed Paimon table function handling for tables with no partition. Resolves [#89690](https://github.com/ClickHouse/ClickHouse/issues/89690). [#89793](https://github.com/ClickHouse/ClickHouse/pull/89793) ([JIaQi](https://github.com/JiaQiTang98)).
* Fix possible logical error during reading of paths and their subcolumns in advanced JSON shared data serialization. Closes [#89805](https://github.com/ClickHouse/ClickHouse/issues/89805). [#89819](https://github.com/ClickHouse/ClickHouse/pull/89819) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix possible stack overflow in data types binary deserialization. Closes [#88710](https://github.com/ClickHouse/ClickHouse/issues/88710). [#89822](https://github.com/ClickHouse/ClickHouse/pull/89822) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix logical error with empty tuple inside `IN` function. Closes [#88343](https://github.com/ClickHouse/ClickHouse/issues/88343). [#89850](https://github.com/ClickHouse/ClickHouse/pull/89850) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Remove injective functions from `GROUP BY` regardless `optimize_injective_functions_in_group_by` in old analyzer for compatibility. Resolves [#89854](https://github.com/ClickHouse/ClickHouse/issues/89854). [#89870](https://github.com/ClickHouse/ClickHouse/pull/89870) ([Raufs Dunamalijevs](https://github.com/rienath)).
* If the merge was interrupted by, for example, a memory limit, the merge mutate background executor will call `cancel` on the merge task without a lock, but, in this case, the partially created resulting part will not be removed (since it was not finished and at this stage was not visible). After that, the merge task will be destroyed, which will trigger the destruction of the resulting part. This will revert the disk transaction and cause the data to be removed from S3. At the end, this garbage cleanup was executed under the merge mutate background executor lock. [#89875](https://github.com/ClickHouse/ClickHouse/pull/89875) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Fix logical error with empty tuple inside `reverse` and `CAST` function. Closes [#89137](https://github.com/ClickHouse/ClickHouse/issues/89137). [#89908](https://github.com/ClickHouse/ClickHouse/pull/89908) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Now ClickHouse will show data lake catalog database in `SHOW DATABASES` query by default. [#89914](https://github.com/ClickHouse/ClickHouse/pull/89914) ([alesapin](https://github.com/alesapin)).
* Fix using native copy on GCS for backups. Because of incorrect client cloning, GCS native copy always failed and used less optimal approach of manual reading and writing the data. [#89923](https://github.com/ClickHouse/ClickHouse/pull/89923) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix buffer size calculation for base32Encode. Calculating base32Encode for column of strings of size smaller than 5 could lead to crashes. Resolves [#89911](https://github.com/ClickHouse/ClickHouse/issues/89911). [#89929](https://github.com/ClickHouse/ClickHouse/pull/89929) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix wrong escaping for `SHOW COLUMNS` and `SHOW FUNCTIONS` queries. [#89942](https://github.com/ClickHouse/ClickHouse/pull/89942) ([alesapin](https://github.com/alesapin)).
* Fix URL validation in MongoDB engine when username contains '@' character. Previously, usernames with '@' would cause an error due to improper encoding. [#89970](https://github.com/ClickHouse/ClickHouse/pull/89970) ([Kai Zhu](https://github.com/nauu)).
* Backported in [#90592](https://github.com/ClickHouse/ClickHouse/issues/90592): Fix possible crash during remote query with `ARRAY JOIN` inside `IN` and enabled `enable_lazy_columns_replication` setting. Resolves [#90361](https://github.com/ClickHouse/ClickHouse/issues/90361). [#89997](https://github.com/ClickHouse/ClickHouse/pull/89997) ([Pavel Kruglov](https://github.com/Avogar)).
* Backported in [#90448](https://github.com/ClickHouse/ClickHouse/issues/90448): Fix inference of bad DateTime64 values from Strings in text formats in some cases. Resolves [#89368](https://github.com/ClickHouse/ClickHouse/issues/89368). [#90013](https://github.com/ClickHouse/ClickHouse/pull/90013) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix logical error caused by empty tuple column in `BSONEachRow` and `MsgPack`. Closes [#89814](https://github.com/ClickHouse/ClickHouse/issues/89814). Closes [#71536](https://github.com/ClickHouse/ClickHouse/issues/71536). [#90018](https://github.com/ClickHouse/ClickHouse/pull/90018) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Backported in [#90457](https://github.com/ClickHouse/ClickHouse/issues/90457): Do size checks when deserializing data from aggregation states and other sources. [#90031](https://github.com/ClickHouse/ClickHouse/pull/90031) ([Raúl Marín](https://github.com/Algunenano)).
* Fix possible 'Invalid number of rows in Chunk' error in JOIN with duplicate columns. Resolves [#89411](https://github.com/ClickHouse/ClickHouse/issues/89411). [#90053](https://github.com/ClickHouse/ClickHouse/pull/90053) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Backported in [#90588](https://github.com/ClickHouse/ClickHouse/issues/90588): Fix possible error `Column with Array type is not represented by ColumnArray column: Replicated` during insertion with usage of `ARRAY JOIN` and enabled `enable_lazy_columns_replication` setting. [#90066](https://github.com/ClickHouse/ClickHouse/pull/90066) ([Pavel Kruglov](https://github.com/Avogar)).
* Allow files starting with dots in user\_files. Closes [#89662](https://github.com/ClickHouse/ClickHouse/issues/89662). [#90079](https://github.com/ClickHouse/ClickHouse/pull/90079) ([Raúl Marín](https://github.com/Algunenano)).
* Backported in [#90647](https://github.com/ClickHouse/ClickHouse/issues/90647): Fix logical error and modulo bug in `numbers` system table when big step size is used. Closes [#83398](https://github.com/ClickHouse/ClickHouse/issues/83398). [#90123](https://github.com/ClickHouse/ClickHouse/pull/90123) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Fix integer overflow in dictionary argument parsing. Closes [#78506](https://github.com/ClickHouse/ClickHouse/issues/78506). [#90171](https://github.com/ClickHouse/ClickHouse/pull/90171) ([Raúl Marín](https://github.com/Algunenano)).
* Backported in [#90468](https://github.com/ClickHouse/ClickHouse/issues/90468): Fix hive partitioning incompatibility preventing smooth upgrade in 25.8 (fixes error `All hive partitioning columns must be present in the schema` during upgrade). [#90202](https://github.com/ClickHouse/ClickHouse/pull/90202) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fixed possible incorrect query results after lightweight updates in `SELECT` queries with the enabled query condition cache. Fixes [#90176](https://github.com/ClickHouse/ClickHouse/issues/90176). Fixes [#90054](https://github.com/ClickHouse/ClickHouse/issues/90054). [#90204](https://github.com/ClickHouse/ClickHouse/pull/90204) ([Anton Popov](https://github.com/CurtizJ)).
* Fix crash in StorageDistributed when parsing malformed shard directory names. [#90243](https://github.com/ClickHouse/ClickHouse/pull/90243) ([Aleksandr Musorin](https://github.com/AVMusorin)).
* Handle implicit conversion from a string to an integer or a boolean in `LogicalExpressionOptimizerPass`. Resolves [#89803](https://github.com/ClickHouse/ClickHouse/issues/89803). [#90245](https://github.com/ClickHouse/ClickHouse/pull/90245) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Fix incorrect formatting of certain skip indexes in the table definition, causing `METADATA_MISMATCH` and breaking creation of new replicas in the Replicated Database. [#90251](https://github.com/ClickHouse/ClickHouse/pull/90251) ([Nikolay Degterinsky](https://github.com/evillique)).
* Backported in [#90381](https://github.com/ClickHouse/ClickHouse/issues/90381): Fixes a row-count mismatch in MergeTreeReaderIndex when the part's only has fewer rows than index\_granularity. Resolves [#89691](https://github.com/ClickHouse/ClickHouse/issues/89691). [#90254](https://github.com/ClickHouse/ClickHouse/pull/90254) ([Peng Jian](https://github.com/fastio)).
* Backported in [#90608](https://github.com/ClickHouse/ClickHouse/issues/90608): Fix bug in reading subcolumns from JSON in compact parts that could lead to `CANNOT_READ_ALL_DATA` error. Resolves [#90264](https://github.com/ClickHouse/ClickHouse/issues/90264). [#90302](https://github.com/ClickHouse/ClickHouse/pull/90302) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix `trim`, `ltrim`, `rtrim` functions not working with two arguments. Closes [#90170](https://github.com/ClickHouse/ClickHouse/issues/90170). [#90305](https://github.com/ClickHouse/ClickHouse/pull/90305) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Backported in [#90625](https://github.com/ClickHouse/ClickHouse/issues/90625): Fix possible logical error in prewhere on non-existing JSON path with index\_granularity\_bytes=0. Resolves [#86924](https://github.com/ClickHouse/ClickHouse/issues/86924). [#90375](https://github.com/ClickHouse/ClickHouse/pull/90375) ([Pavel Kruglov](https://github.com/Avogar)).
* Backported in [#90484](https://github.com/ClickHouse/ClickHouse/issues/90484): Fixed a bug in `L2DistanceTransposed` that caused crashes when the precision argument exceeded valid range. Closes [#90401](https://github.com/ClickHouse/ClickHouse/issues/90401). [#90405](https://github.com/ClickHouse/ClickHouse/pull/90405) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Backported in [#90577](https://github.com/ClickHouse/ClickHouse/issues/90577): Fixed incorrect distance calculations in `L2DistanceTransposed` when using array reference vectors (which default to `Array(Float64))` with `QBit` columns of non-`Float64` element types (`Float32`, `BFloat16`). The function now automatically casts the reference vector to match the `QBit`'s element type. Resolves [#89976](https://github.com/ClickHouse/ClickHouse/issues/89976). [#90485](https://github.com/ClickHouse/ClickHouse/pull/90485) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Backported in [#90601](https://github.com/ClickHouse/ClickHouse/issues/90601): Fix logical error caused by a rare case in `equals` function. Closes [#88142](https://github.com/ClickHouse/ClickHouse/issues/88142). [#90557](https://github.com/ClickHouse/ClickHouse/pull/90557) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Fix `CoalescingMergeTree` for `Tuple` types. [#88828](https://github.com/ClickHouse/ClickHouse/pull/88828) ([scanhex12](https://github.com/scanhex12)).
#### Build/Testing/Packaging Improvement
* Fix Connection refused error for running ClickHouse in Docker with initdb SQL scripts and overridden TCP port. [#88042](https://github.com/ClickHouse/ClickHouse/pull/88042) ([Grigorii](https://github.com/GSokol)).
* Experimentally support e2k as a new platform for ClickHouse. [#90159](https://github.com/ClickHouse/ClickHouse/pull/90159) ([Ramil Sattarov](https://github.com/r-a-sattarov)).
* Remove the remaining use of `FindPackage` from CMake. Builds should not depend on the system packages. [#89380](https://github.com/ClickHouse/ClickHouse/pull/89380) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Use compiler cache in builds during CMake configuration (e.g. `protoc`). [#89613](https://github.com/ClickHouse/ClickHouse/pull/89613) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Use FreeBSD 13.4 sysroot. [#89617](https://github.com/ClickHouse/ClickHouse/pull/89617) ([Konstantin Bogdanov](https://github.com/thevar1able)).
ClickHouse release 25.10, 2025-10-31
#### Backward Incompatible Change
* Changed default `schema_inference_make_columns_nullable` setting to respect column `Nullable`-ness information from Parquet/ORC/Arrow metadata, instead of making everything Nullable. No change for text formats. [#71499](https://github.com/ClickHouse/ClickHouse/pull/71499) ([Michael Kolupaev](https://github.com/al13n321)).
* The query result cache will ignore the `log_comment` setting, so that changing only the `log_comment` on a query no longer forces a cache miss. There is a small chance users intentionally segmented their cache by varying `log_comment`. This change alters that behavior and is therefore backward incompatible. Please use setting `query_cache_tag` for this purpose. [#79878](https://github.com/ClickHouse/ClickHouse/pull/79878) ([filimonov](https://github.com/filimonov)).
* In previous versions, queries with table functions named the same way as the implementation functions for operators were formatted inconsistently. Closes [#81601](https://github.com/ClickHouse/ClickHouse/issues/81601). Closes [#81977](https://github.com/ClickHouse/ClickHouse/issues/81977). Closes [#82834](https://github.com/ClickHouse/ClickHouse/issues/82834). Closes [#82835](https://github.com/ClickHouse/ClickHouse/issues/82835). EXPLAIN SYNTAX queries will not always format operators - the new behavior better reflects the purpose of explaining syntax. `clickhouse-format`, `formatQuery`, and similar will not format functions as operators if the query contained them in a functional form. [#82825](https://github.com/ClickHouse/ClickHouse/pull/82825) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Forbid using the `Dynamic` type in `JOIN` keys. It could lead to unexpected results when a value of `Dynamic` type is compared to a non-`Dynamic` type. It's better to cast the `Dynamic` column to the required type. [#86358](https://github.com/ClickHouse/ClickHouse/pull/86358) ([Pavel Kruglov](https://github.com/Avogar)).
* `storage_metadata_write_full_object_key` server option is turned on by default, it can't be set off now. this is backward compatible change. This is only for you attention. This change is forward compatible only with 25.x releases. That means that you could downgrade only on any 25.x release in case you have to rollback the new release. [#87335](https://github.com/ClickHouse/ClickHouse/pull/87335) ([Sema Checherinda](https://github.com/CheSema)).
* Decrease `replicated_deduplication_window_seconds` from one week down to one hour in order to store less znode on zookeeper when insertion rate is low. [#87414](https://github.com/ClickHouse/ClickHouse/pull/87414) ([Sema Checherinda](https://github.com/CheSema)).
* Rename setting `query_plan_use_new_logical_join_step` to `query_plan_use_logical_join_step`. [#87679](https://github.com/ClickHouse/ClickHouse/pull/87679) ([Vladimir Cherkasov](https://github.com/vdimir)).
* The new syntax allows the tokenizer parameter for the text index to be more expressive. [#87997](https://github.com/ClickHouse/ClickHouse/pull/87997) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Renamed functions `searchAny` and `searchAll` to `hasAnyTokens` and `hasAllTokens` for better consistency with existing function `hasToken`. [#88109](https://github.com/ClickHouse/ClickHouse/pull/88109) ([Robert Schulze](https://github.com/rschu1ze)).
* Remove `cache_hits_threshold` from filesystem cache. This feature was added by an external contributor before we had SLRU cache policy, and now that we have it - it does not make sense to support both. [#88344](https://github.com/ClickHouse/ClickHouse/pull/88344) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Two slight changes to how `min_free_disk_ratio_to_perform_insert` and `min_free_disk_bytes_to_perform_insert` settings work: - use unreserved instead of available bytes to determine if an insert should be rejected. This is probably not crucial if the reservations for background merges and mutations are small compared to the configured thresholds, but it seems more correct. - Don't apply these settings to system tables. The reasoning for this is that we still want tables like `query_log` to be updated. This helps a lot with debugging. Data written to system tables is usually small compared to actual data, so they should be able to continue for much longer with a reasonable `min_free_disk_ratio_to_perform_insert` threshold. [#88468](https://github.com/ClickHouse/ClickHouse/pull/88468) ([c-end](https://github.com/c-end)).
* Enable async mode for Keeper's internal replication. Keeper will preserve the same behavior as before with possible performance improvements. If you are updating from a version older than 23.9, you need to either update first to 23.9+ and than to 25.10+. You can also set `keeper_server.coordination_settings.async_replication` to 0 before update and enable it after update is done. [#88515](https://github.com/ClickHouse/ClickHouse/pull/88515) ([Antonio Andelic](https://github.com/antonio2368)).
#### New Feature
* Add support for negative `LIMIT` and negative `OFFSET`. Closes [#28913](https://github.com/ClickHouse/ClickHouse/issues/28913). [#88411](https://github.com/ClickHouse/ClickHouse/pull/88411) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* The `Alias` engine creates a proxy to another table. All read and write operations are forwarded to the target table, while the alias itself stores no data and only maintains a reference to the target table. [#87965](https://github.com/ClickHouse/ClickHouse/pull/87965) ([Kai Zhu](https://github.com/nauu)).
* Full support of operator `IS NOT DISTINCT FROM` (`<=>`). [#88155](https://github.com/ClickHouse/ClickHouse/pull/88155) ([simonmichal](https://github.com/simonmichal)).
* Added an ability to automatically create statistics on all suitable columns in `MergeTree` tables. Added table-level setting `auto_statistics_types` which stores comma-separated types of statistics to create (e.g. `auto_statistics_types = 'minmax, uniq, countmin'`). [#87241](https://github.com/ClickHouse/ClickHouse/pull/87241) ([Anton Popov](https://github.com/CurtizJ)).
* A new bloom filter index for text, `sparse_gram`. [#79985](https://github.com/ClickHouse/ClickHouse/pull/79985) ([scanhex12](https://github.com/scanhex12)).
* A new `conv` function for converting numbers between bases, currently supports bases from `2-36`. [#83058](https://github.com/ClickHouse/ClickHouse/pull/83058) ([hp](https://github.com/hp77-creator)).
* Added `LIMIT BY ALL` syntax support. Similar to `GROUP BY ALL` and `ORDER BY ALL`, `LIMIT BY ALL` automatically expands to use all non-aggregate expressions from the SELECT clause as LIMIT BY keys. For example, `SELECT id, name, count(*) FROM table GROUP BY id LIMIT 1 BY ALL` is equivalent to `SELECT id, name, count(*) FROM table GROUP BY id LIMIT 1 BY id, name`. This feature simplifies queries when you want to limit by all selected non-aggregate columns without explicitly listing them. Closes [#59152](https://github.com/ClickHouse/ClickHouse/issues/59152). [#84079](https://github.com/ClickHouse/ClickHouse/pull/84079) ([Surya Kant Ranjan](https://github.com/iit2009046)).
* Add support for querying Apache Paimon in ClickHouse. This integration would enable ClickHouse users to directly interact with Paimon's data lake storage. [#84423](https://github.com/ClickHouse/ClickHouse/pull/84423) ([JIaQi](https://github.com/JiaQiTang98)).
* Added `studentTTestOneSample` aggregate function. [#85436](https://github.com/ClickHouse/ClickHouse/pull/85436) ([Dylan](https://github.com/DylanBlakemore)).
* Aggregate function `quantilePrometheusHistogram`, which accepts the upper bounds and cumulative values of histogram buckets as arguments, and performs a linear interpolation between the upper and lower bounds of the bucket in which the quantile position is found. Behaves similarly to the PromQL `histogram_quantile` function on classic histograms. [#86294](https://github.com/ClickHouse/ClickHouse/pull/86294) ([Stephen Chi](https://github.com/stephchi0)).
* A new system table for delta lake metadata files. [#87263](https://github.com/ClickHouse/ClickHouse/pull/87263) ([scanhex12](https://github.com/scanhex12)).
* Add `ALTER TABLE REWRITE PARTS` - rewrites the table parts from scratch, by using all new settings (since some, like `use_const_adaptive_granularity`, will be applied only for new parts). [#87774](https://github.com/ClickHouse/ClickHouse/pull/87774) ([Azat Khuzhin](https://github.com/azat)).
* Add `SYSTEM RECONNECT ZOOKEEPER` command to force zookeeper disconnect and reconnect ([https://github.com/ClickHouse/ClickHouse/issues/87317](https://github.com/ClickHouse/ClickHouse/issues/87317)). [#87318](https://github.com/ClickHouse/ClickHouse/pull/87318) ([Pradeep Chhetri](https://github.com/chhetripradeep)).
* Limit the number of named collections through setting `max_named_collection_num_to_warn` and `max_named_collection_num_to_throw`. Add new metric `NamedCollection` and error `TOO_MANY_NAMED_COLLECTIONS`. [#87343](https://github.com/ClickHouse/ClickHouse/pull/87343) ([Pablo Marcos](https://github.com/pamarcos)).
* Added optimized case-insensitive variants of `startsWith` and `endsWith` functions: `startsWithCaseInsensitive`, `endsWithCaseInsensitive`, `startsWithCaseInsensitiveUTF8`, and `endsWithCaseInsensitiveUTF8`. [#87374](https://github.com/ClickHouse/ClickHouse/pull/87374) ([Guang Zhao](https://github.com/zheguang)).
* Adds a way to provide `WORKLOAD` and `RESOURCE` definitions in SQL using the server configuration "resources\_and\_workloads" section. [#87430](https://github.com/ClickHouse/ClickHouse/pull/87430) ([Sergei Trifonov](https://github.com/serxa)).
* Add a new table setting `min_level_for_wide_part` that allows specifying the minimum level for a part to be created as a wide part. [#88179](https://github.com/ClickHouse/ClickHouse/pull/88179) ([Christoph Wurm](https://github.com/cwurm)).
* Add recursive variants of `cp`-`cpr` and `mv`-`mvr` commands in Keeper client. [#88570](https://github.com/ClickHouse/ClickHouse/pull/88570) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Added session setting to exclude list of skip indexes from materialization on inserts (`exclude_materialize_skip_indexes_on_insert`). Added merge tree table setting to exclude list of skip indexes from materialization during merge (`exclude_materialize_skip_indexes_on_merge`). [#87252](https://github.com/ClickHouse/ClickHouse/pull/87252) ([George Larionov](https://github.com/george-larionov)).
#### Experimental Feature
* Implement `QBit` data type that stores vectors in bit-sliced format and `L2DistanceTransposed` function that allows approximate vector search where precision-speed trade-off is controlled by a parameter. [#87922](https://github.com/ClickHouse/ClickHouse/pull/87922) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Functions `searchAll` and `searchAny` now work on top of columns without text columns. In those cases, they use the default tokenizer. [#87722](https://github.com/ClickHouse/ClickHouse/pull/87722) ([Jimmy Aguilar Mena](https://github.com/Ergus)).
#### Performance Improvement
* Implement lazy columns replication in JOIN and ARRAY JOIN. Avoid converting special columns representation like Sparse and Replicated to full columns in some output formats. This avoids unnecessary data copy in memory. [#88752](https://github.com/ClickHouse/ClickHouse/pull/88752) ([Pavel Kruglov](https://github.com/Avogar)).
* Add optional `.size` subcolumn serialization for top-level String columns in MergeTree tables to improve compression and enable efficient subcolumn access. Introduce new MergeTree settings for serialization version control and expression optimization for empty strings. [#82850](https://github.com/ClickHouse/ClickHouse/pull/82850) ([Amos Bird](https://github.com/amosbird)).
* Support for read in order for Iceberg. [#88454](https://github.com/ClickHouse/ClickHouse/pull/88454) ([scanhex12](https://github.com/scanhex12)).
* Speed up some JOIN queries by building a bloom filter from the right subtree at runtime and pass this filter to the scan in the left subtree. This can be beneficial for queries like `SELECT avg(o_totalprice) FROM orders, customer, nation WHERE c_custkey = o_custkey AND c_nationkey=n_nationkey AND n_name = 'FRANCE'`. [#84772](https://github.com/ClickHouse/ClickHouse/pull/84772) ([Alexander Gololobov](https://github.com/davenger)).
* Improved query performance by refactoring the order and integration of Query Condition Cache (QCC) with index analysis. QCC filtering is now applied before primary key and skip index analysis, reducing unnecessary index computation. Index analysis has been extended to support multiple range filters, and its filtering results are now stored back into the QCC. This significantly speeds up queries where index analysis dominates execution time—especially those relying on skip indexes (e.g. vector or inverted indexes). [#82380](https://github.com/ClickHouse/ClickHouse/pull/82380) ([Amos Bird](https://github.com/amosbird)).
* A bunch of micro-optimizations to speed up small queries. [#83096](https://github.com/ClickHouse/ClickHouse/pull/83096) ([Raúl Marín](https://github.com/Algunenano)).
* Compress logs and profile events in the native protocol. On clusters with 100+ replicas, uncompressed profile events take 1..10 MB/sec, and the progress bar is sluggish on slow Internet connections. This closes [#82533](https://github.com/ClickHouse/ClickHouse/issues/82533). [#83586](https://github.com/ClickHouse/ClickHouse/pull/83586) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Improve the performance of case sensitive string search (operations such as filtering, e.g. `WHERE URL LIKE '%google%'`) by using the [StringZilla](https://github.com/ashvardanian/StringZilla) library, using SIMD CPU instructions when available. [#84161](https://github.com/ClickHouse/ClickHouse/pull/84161) ([Raúl Marín](https://github.com/Algunenano)).
* Reduce memory allocation and memory copy when select from an aggregating merge tree table with FINAL when the table has columns with type `SimpleAggregateFunction(anyLast)`. [#84428](https://github.com/ClickHouse/ClickHouse/pull/84428) ([Duc Canh Le](https://github.com/canhld94)).
* Provides a logic regarding pushing down the disjunction JOIN predicates. Example: in TPC-H Q7 for a condition on 2 tables n1 and n2 like `(n1.n_name = 'FRANCE' AND n2.n_name = 'GERMANY') OR (n1.n_name = 'GERMANY' AND n2.n_name = 'FRANCE')` we extract separate partial filters for each table `n1.n_name = 'FRANCE' OR n1.n_name = 'GERMANY'` for n1 and `n2.n_name = 'GERMANY' OR n2.n_name = 'FRANCE'` for n2. [#84735](https://github.com/ClickHouse/ClickHouse/pull/84735) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Improves performance of `LIKE` with prefix or suffix by using the new default setting `optimize_rewrite_like_perfect_affix`. [#85920](https://github.com/ClickHouse/ClickHouse/pull/85920) ([Guang Zhao](https://github.com/zheguang)).
* Fix performance degradation caused by large serialized key while grouping by multiple string/number columns. It is a follow-up of [#83884](https://github.com/ClickHouse/ClickHouse/pull/83884). [#85924](https://github.com/ClickHouse/ClickHouse/pull/85924) ([李扬](https://github.com/taiyang-li)).
* Add new `joined_block_split_single_row` setting to reduce memory usage in hash joins with many matches per key. This allows hash join results to be chunked even within matches for a single left table row, which is particularly useful when one row from the left table matches thousands or millions of rows from the right table. Previously, all matches had to be materialized at once in memory. This reduces peak memory usage but may increase CPU usage. [#87913](https://github.com/ClickHouse/ClickHouse/pull/87913) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Improvements to SharedMutex (improve the performance on a large number of concurrent queries). [#87491](https://github.com/ClickHouse/ClickHouse/pull/87491) ([Raúl Marín](https://github.com/Algunenano)).
* Improved performance of building text index for documents that contain mostly non-frequent tokens. [#87546](https://github.com/ClickHouse/ClickHouse/pull/87546) ([Anton Popov](https://github.com/CurtizJ)).
* Speed up the common case of the Field destructor (improve the performance on a large number of small queries). [#87631](https://github.com/ClickHouse/ClickHouse/pull/87631) ([Raúl Marín](https://github.com/Algunenano)).
* Skip runtime hash table statistics recalculation during JOIN optimization (improves the performance of all queries with JOINs). Added new profile events `JoinOptimizeMicroseconds` and `QueryPlanOptimizeMicroseconds`. [#87683](https://github.com/ClickHouse/ClickHouse/pull/87683) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Enable saving marks in cache and avoid direct IO for the MergeTreeLazy reader. This improves the performance of queries with ORDER BY and small LIMIT. [#87989](https://github.com/ClickHouse/ClickHouse/pull/87989) ([Nikita Taranov](https://github.com/nickitat)).
* SELECT query with `FINAL` clause on.a `ReplacingMergeTree` table with the `is_deleted` column now executes faster because of improved parallelization from two existing optimizations: 1. `do_not_merge_across_partitions_select_final` optimization for partitions of the table that have only a single `part`; 2. Split other selected ranges of the table into `intersecting / non-intersecting` and only intersecting ranges have to pass through FINAL merging transform. [#88090](https://github.com/ClickHouse/ClickHouse/pull/88090) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Reduce the impact of not using fail points (the default code path when the debugging is not active). [#88196](https://github.com/ClickHouse/ClickHouse/pull/88196) ([Raúl Marín](https://github.com/Algunenano)).
* Avoid full scan for `system.tables` with filter by `uuid` (Can be useful if you have only UUID from logs or zookeeper path). [#88379](https://github.com/ClickHouse/ClickHouse/pull/88379) ([Azat Khuzhin](https://github.com/azat)).
* Improved performance of functions `tokens`, `hasAllTokens`, `hasAnyTokens`. [#88416](https://github.com/ClickHouse/ClickHouse/pull/88416) ([Anton Popov](https://github.com/CurtizJ)).
* Inline `AddedColumns::appendFromBlock` for slightly better JOIN performance in some cases. [#88455](https://github.com/ClickHouse/ClickHouse/pull/88455) ([Nikita Taranov](https://github.com/nickitat)).
* Client autocompletion is faster and more consistent by using `system.completions` rather than issuing multiple system-table queries. [#84694](https://github.com/ClickHouse/ClickHouse/pull/84694) ([|2ustam](https://github.com/RuS2m)).
* Add new `dictionary_block_frontcoding_compression` text index parameter to control the dictionary compression. By default, it is enabled to use the `front-coding` compression. [#87175](https://github.com/ClickHouse/ClickHouse/pull/87175) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Squash data from all threads before inserting to materialized views depending on the settings `min_insert_block_size_rows_for_materialized_views` and `min_insert_block_size_bytes_for_materialized_views`. Previously, if `parallel_view_processing` was enabled, each thread inserting to a specific materailized view would squash insert independently which could lead to higher number of generated parts. [#87280](https://github.com/ClickHouse/ClickHouse/pull/87280) ([Antonio Andelic](https://github.com/antonio2368)).
* Add setting `temporary_files_buffer_size` to control size of the buffer for temporary files writers. \* Optimize memory consumption of `scatter` operation (used, for example in grace hash join) for `LowCardinality` columns. [#88237](https://github.com/ClickHouse/ClickHouse/pull/88237) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Added support of direct reading from text indexes with parallel replicas. Improved performance of reading text indexes from object storage. [#88262](https://github.com/ClickHouse/ClickHouse/pull/88262) ([Anton Popov](https://github.com/CurtizJ)).
* Queries with tables from Data Lakes catalogs will use parallel replicas for distributed processing. [#88273](https://github.com/ClickHouse/ClickHouse/pull/88273) ([scanhex12](https://github.com/scanhex12)).
* The internal heuristic for tuning of the background merges algorithm, named "to\_remove\_small\_parts\_at\_right" will be executed before the calculation of the merge range score. Before that, the merge selector was choosing the wide merge, and after that, it filtered its suffix. Fixes: [#85374](https://github.com/ClickHouse/ClickHouse/issues/85374). [#88736](https://github.com/ClickHouse/ClickHouse/pull/88736) ([Mikhail Artemenko](https://github.com/Michicosun)).
#### Improvement
* Now the function `generateSerialID` supports a non-constant argument with the series name. Closes [#83750](https://github.com/ClickHouse/ClickHouse/issues/83750). [#88270](https://github.com/ClickHouse/ClickHouse/pull/88270) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Added optional `start_value` parameter to `generateSerialID` function to specify custom starting values for new series. [#88085](https://github.com/ClickHouse/ClickHouse/pull/88085) ([Manuel](https://github.com/raimannma)).
* Add `--semicolons_inline` option in `clickhouse-format` to format queries so that semicolons are placed on the last line instead of on a new line. [#88018](https://github.com/ClickHouse/ClickHouse/pull/88018) ([Jan Rada](https://github.com/ZelvaMan)).
* Allow configuring server-level throttling when the configuration is overridden in Keeper. Closes [#73964](https://github.com/ClickHouse/ClickHouse/issues/73964). [#74066](https://github.com/ClickHouse/ClickHouse/pull/74066) ([JIaQi](https://github.com/JiaQiTang98)).
* `mannWhitneyUTest` no longer throws an exception when both samples contain only identical values. Now returns a valid result, consistent with SciPy. This closes: [#79814](https://github.com/ClickHouse/ClickHouse/issues/79814). [#80009](https://github.com/ClickHouse/ClickHouse/pull/80009) ([DeanNeaht](https://github.com/DeanNeaht)).
* Rewrite disk object storage transaction removes previous remote blobs if metadata transaction is committed. [#81787](https://github.com/ClickHouse/ClickHouse/pull/81787) ([Sema Checherinda](https://github.com/CheSema)).
* Fixed optimization pass for redundant equal expression when `LowCardinality` of the resulting type differs before and after optimization. [#82651](https://github.com/ClickHouse/ClickHouse/pull/82651) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* When HTTP clients set the header `X-ClickHouse-100-Continue: defer` in addition to `Expect: 100-continue`, ClickHouse doesn't send send a `100 Continue` response to the client until after quota validation passes, preventing waste of network bandwidth from transmitting request bodies that will be thrown away anyways. This is relevant for INSERT queries where the query can be sent in the URL query string and the data is sent in the request body. Aborting a request without sending the full body prevents connection reuse with HTTP/1.1, but the additional latency introduced by opening new connections is usually insignificant compared to total INSERT duration with large amounts of data. [#84304](https://github.com/ClickHouse/ClickHouse/pull/84304) ([c-end](https://github.com/c-end)).
* Mask S3 credentials in logs when using DATABASE ENGINE = Backup with S3 storage. [#85336](https://github.com/ClickHouse/ClickHouse/pull/85336) ([Kenny Sun](https://github.com/hwabis)).
* Make query plan optimizations visible to the correlated subquery input subplan by postponing it's materialization. Part of [#79890](https://github.com/ClickHouse/ClickHouse/issues/79890). [#85455](https://github.com/ClickHouse/ClickHouse/pull/85455) ([Dmitry Novik](https://github.com/novikd)).
* A change for SYSTEM DROP DATABASE REPLICA: - When dropping with database or drop the whole replica: it also drops replica for each table of the database - If 'WITH TABLES' is provided, drop replica for each storage - Otherwise, the logic is unchanged, only drop replica on the databases - When dropping a database replica with the keeper path: - If 'WITH TABLES' is provided: - Restore the database as Atomic - Restore RMT tables from statement in Keeper - Drop the database (restored tables are also dropped) - Otherwise, only drop replica on the provided keeper path. [#85637](https://github.com/ClickHouse/ClickHouse/pull/85637) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Fix inconsistent formatting of TTL when it contains a `materialize` function. Closes [#82828](https://github.com/ClickHouse/ClickHouse/issues/82828). [#85749](https://github.com/ClickHouse/ClickHouse/pull/85749) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Iceberg table state is not stored in a storage object anymore. This should make Iceberg in ClickHouse usable with concurrent queries. [#86062](https://github.com/ClickHouse/ClickHouse/pull/86062) ([Daniil Ivanik](https://github.com/divanik)).
* Make bucket lock in S3Queue ordered mode a persistent mode, similar to processing nodes in case `use_persistent_processing_nodes = 1`. Add keeper fault injection in tests. [#86628](https://github.com/ClickHouse/ClickHouse/pull/86628) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Provide hints when a user has a typo in the format name. Closes [#86761](https://github.com/ClickHouse/ClickHouse/issues/86761). [#87092](https://github.com/ClickHouse/ClickHouse/pull/87092) ([flynn](https://github.com/ucasfl)).
* Remote replicas will skip index analysis when there are no projections. [#87096](https://github.com/ClickHouse/ClickHouse/pull/87096) ([zoomxi](https://github.com/zoomxi)).
* Allow disabling utf8 encoding for ytsaurus table. [#87150](https://github.com/ClickHouse/ClickHouse/pull/87150) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* Disable `s3_slow_all_threads_after_retryable_error` by default. [#87198](https://github.com/ClickHouse/ClickHouse/pull/87198) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Rename table function `arrowflight` to `arrowFlight`. [#87249](https://github.com/ClickHouse/ClickHouse/pull/87249) ([Vitaly Baranov](https://github.com/vitlibar)).
* Updated `clickhouse-benchmark` to accept using `-` if in place of `_` in its cli flags. [#87251](https://github.com/ClickHouse/ClickHouse/pull/87251) ([Ahmed Gouda](https://github.com/0xgouda)).
* Make flushing to `system.crash_log` in signal handling synchronous. [#87253](https://github.com/ClickHouse/ClickHouse/pull/87253) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Added a setting `inject_random_order_for_select_without_order_by` which injects `ORDER BY rand()` into top-level `SELECT` queries without `ORDER BY` clause. [#87261](https://github.com/ClickHouse/ClickHouse/pull/87261) ([Rui Zhang](https://github.com/zhangruiddn)).
* Improve `joinGet` error message so that it properly states that the number of `join_keys` is not the same as the number of `right_table_keys`. [#87279](https://github.com/ClickHouse/ClickHouse/pull/87279) ([Isak Ellmer](https://github.com/spinojara)).
* Add the ability to check an arbitrary Keeper node's stat during the write tx. This can help with ABA problem detection. [#87282](https://github.com/ClickHouse/ClickHouse/pull/87282) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Redirect heavy ytsaurus requests to heavy proxies. [#87342](https://github.com/ClickHouse/ClickHouse/pull/87342) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* Fix rollbacks of unlink/rename/removeRecursive/removeDirectory/etc operations and also hardlink counts in any possible workloads for metadata from disk transactions, and simplifies the interfaces to make them more generic so that they can be reused in other meta stores. [#87358](https://github.com/ClickHouse/ClickHouse/pull/87358) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Added `keeper_server.tcp_nodelay` configuration parameter that allows disabling `TCP_NODELAY` for Keeper. [#87363](https://github.com/ClickHouse/ClickHouse/pull/87363) (Copilot).
* Support `--connection` in `clickhouse-benchmarks`. It is the same as supported by `clickhouse-client`, you can specify predefined connections in client `config.xml`/`config.yaml` under `connections_credentials` path, to avoid explicitly specifying user/password via command line arguments. Add support for `--accept-invalid-certificate` into `clickhouse-benchmark`. [#87370](https://github.com/ClickHouse/ClickHouse/pull/87370) ([Azat Khuzhin](https://github.com/azat)).
* Now setting `max_insert_threads` will take effect on Iceberg tables. [#87407](https://github.com/ClickHouse/ClickHouse/pull/87407) ([alesapin](https://github.com/alesapin)).
* Add histogram and dimensional metrics to `PrometheusMetricsWriter`. This way, the `PrometheusRequestHandler` handler will have all the essential metrics and can be used for reliable and low-overhead metric collection in the cloud. [#87521](https://github.com/ClickHouse/ClickHouse/pull/87521) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Function `hasToken` now returns zero matches for the empty token (whereas this previously threw an exception). [#87564](https://github.com/ClickHouse/ClickHouse/pull/87564) ([Jimmy Aguilar Mena](https://github.com/Ergus)).
* Add text index support for `Array` and `Map` (`mapKeys` and `mapValues`) values. The supported functions are `mapContainsKey` and `has`. [#87602](https://github.com/ClickHouse/ClickHouse/pull/87602) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Add a new `ZooKeeperSessionExpired` metric which indicates the number of expired global ZooKeeper sessions. [#87613](https://github.com/ClickHouse/ClickHouse/pull/87613) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Use S3 storage client with backup-specific settings (for example, backup\_slow\_all\_threads\_after\_retryable\_s3\_error) for server-side (native) copy to a backup destination. Make s3\_slow\_all\_threads\_after\_retryable\_error obsolete. [#87660](https://github.com/ClickHouse/ClickHouse/pull/87660) ([Julia Kartseva](https://github.com/jkartseva)).
* Fix incorrect handling of settings `max_joined_block_size_rows` and `max_joined_block_size_bytes` during query plan serialization with experimental `make_distributed_plan`. [#87675](https://github.com/ClickHouse/ClickHouse/pull/87675) ([Vladimir Cherkasov](https://github.com/vdimir)).
* The setting `enable_http_compression` is now the default. This means that if a client accepts HTTP compression, the server will use it. However, this change has certain downsides. The client can request a heavy compression method, such as `bzip2`, which is unreasonable, and it will increase the resource consumption of the server (but this will be visible only when large results are transferred). The client can request `gzip`, which is not that bad, but suboptimal compared to `zstd`. Closes [#71591](https://github.com/ClickHouse/ClickHouse/issues/71591). [#87703](https://github.com/ClickHouse/ClickHouse/pull/87703) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Added a new entry in `system.server_settings`, `keeper_hosts` that exposes the list of \[Zoo]Keeper hosts ClickHouse can connect to. [#87718](https://github.com/ClickHouse/ClickHouse/pull/87718) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Add `from` and `to` values to the system dashboards to facilitate historical investigations. [#87823](https://github.com/ClickHouse/ClickHouse/pull/87823) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
* Add more information for performance tracking in Iceberg SELECTs. [#87903](https://github.com/ClickHouse/ClickHouse/pull/87903) ([Daniil Ivanik](https://github.com/divanik)).
* Filesystem cache improvement: reuse cache priority iterator among threads concurrently reserving space in cache. [#87914](https://github.com/ClickHouse/ClickHouse/pull/87914) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Add ability to limit requests for `Keeper` (`max_request_size` setting, same as `jute.maxbuffer` for `ZooKeeper`, default OFF for backward compatibility, will be set in the next releases). [#87952](https://github.com/ClickHouse/ClickHouse/pull/87952) ([Azat Khuzhin](https://github.com/azat)).
* Make `clickhouse-benchmark` to not include stacktraces in error messages by default. [#87954](https://github.com/ClickHouse/ClickHouse/pull/87954) ([Ahmed Gouda](https://github.com/0xgouda)).
* Avoid utilizing thread pool asynchonous marks loading (`load_marks_asynchronously=1`) when marks are in cache (since the pool can be under pressure and queries will pay penalty for this even if the marks already in cache). [#87967](https://github.com/ClickHouse/ClickHouse/pull/87967) ([Azat Khuzhin](https://github.com/azat)).
* Ytsaurus: allow create table/table functions/dictionaries with subset of columns. [#87982](https://github.com/ClickHouse/ClickHouse/pull/87982) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* From now `system.zookeeper_connection_log` is enabled by default and it can be used to get information about Keeper sessions. [#88011](https://github.com/ClickHouse/ClickHouse/pull/88011) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Make TCP and HTTP behavior consistent when there duplicated external tables are passed. HTTP allows a temporary table to be passed several times. [#88032](https://github.com/ClickHouse/ClickHouse/pull/88032) ([Sema Checherinda](https://github.com/CheSema)).
* Remove custom MemoryPools for reading Arrow/ORC/Parquet. This component seems unneeded after [#84082](https://github.com/ClickHouse/ClickHouse/pull/84082) because now we track all the allocations regardless. [#88035](https://github.com/ClickHouse/ClickHouse/pull/88035) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Allow to create `Replicated` database without arguments. [#88044](https://github.com/ClickHouse/ClickHouse/pull/88044) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* `clickhouse-keeper-client`: Add support to connect to TLS port of clickhouse-keeper, kept flag names same as in the clickhouse-client. [#88065](https://github.com/ClickHouse/ClickHouse/pull/88065) ([Pradeep Chhetri](https://github.com/chhetripradeep)).
* Added a new profile event to track the number of times that a background merge was rejected due to exceeding memory limits. [#88084](https://github.com/ClickHouse/ClickHouse/pull/88084) ([Grant Holly](https://github.com/grantholly-clickhouse)).
* Enables the analyzer for CREATE/ALTER TABLE column default expression validation. [#88087](https://github.com/ClickHouse/ClickHouse/pull/88087) ([Max Justus Spransy](https://github.com/maxjustus)).
* Internal query planning improvement: use JoinStepLogical for `CROSS JOIN`. [#88151](https://github.com/ClickHouse/ClickHouse/pull/88151) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Added alias for `hasAnyTokens` (`hasAnyToken`) and `hasAllTokens` (`hasAllToken`) functions. [#88162](https://github.com/ClickHouse/ClickHouse/pull/88162) ([George Larionov](https://github.com/george-larionov)).
* Enable global sampling profiler (which means - even for server threads not related to queries) by default: collect stacktraces of all threads every 10 seconds of CPU and real time. [#88209](https://github.com/ClickHouse/ClickHouse/pull/88209) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Update Azure SDK to include 'Content-Length' fix that is seen with copy and create container functionalities. [#88278](https://github.com/ClickHouse/ClickHouse/pull/88278) ([Smita Kulkarni](https://github.com/SmitaRKulkarni)).
* Make function `lag` case insensitive for compatibility with MySQL. [#88322](https://github.com/ClickHouse/ClickHouse/pull/88322) ([Lonny Kapelushnik](https://github.com/lonnylot)).
* Allow `clickhouse-local` to start from the `clickhouse-server` directory. In previous versions, it produced an error `Cannot parse UUID: .` Now you can start clickhouse-local and manipulate the server's databases without starting the server. [#88383](https://github.com/ClickHouse/ClickHouse/pull/88383) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add config `keeper_server.coordination_settings.check_node_acl_on_remove`. If enabled, before each delete of a node, ACLs of both the node itself and parent node will be verified. Otherwise, only the ACL of the parent node will be verified. [#88513](https://github.com/ClickHouse/ClickHouse/pull/88513) ([Antonio Andelic](https://github.com/antonio2368)).
* `JSON` columns are now pretty printed when using `Vertical` format. Closes [#81794](https://github.com/ClickHouse/ClickHouse/issues/81794). [#88524](https://github.com/ClickHouse/ClickHouse/pull/88524) ([Frank Rosner](https://github.com/FRosner)).
* Store `clickhouse-client` files (e.g. query history) in places described by [XDG Base Directories](https://specifications.freedesktop.org/basedir-spec/latest/index.html) specification instead of root of home directory. `~/.clickhouse-client-history` will still be used if it is already present. [#88538](https://github.com/ClickHouse/ClickHouse/pull/88538) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fixes memory leak due to `GLOBAL IN` ([https://github.com/ClickHouse/ClickHouse/issues/88615](https://github.com/ClickHouse/ClickHouse/issues/88615)). [#88617](https://github.com/ClickHouse/ClickHouse/pull/88617) ([pranavmehta94](https://github.com/pranavmehta94)).
* Added overload to hasAny/hasAllTokens to accept a string input. [#88679](https://github.com/ClickHouse/ClickHouse/pull/88679) ([George Larionov](https://github.com/george-larionov)).
* Add a step to postinstall script for `clickhouse-keeper` which enables starting on boot. [#88746](https://github.com/ClickHouse/ClickHouse/pull/88746) ([YenchangChan](https://github.com/YenchangChan)).
* Check credentials in the Web UI only on pasting, rather than on every key press. This avoids a problem with misconfigured LDAP servers. This closes [#85777](https://github.com/ClickHouse/ClickHouse/issues/85777). [#88769](https://github.com/ClickHouse/ClickHouse/pull/88769) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Limit exception message length when a constraint is violated. In previous versions, you could get a very long exception message when a very long string was inserted, and it ended up being written in the query\_log. Closes [#87032](https://github.com/ClickHouse/ClickHouse/issues/87032). [#88801](https://github.com/ClickHouse/ClickHouse/pull/88801) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix requesting the structure of a dataset from the ArrowFlight server when creating a table. [#87542](https://github.com/ClickHouse/ClickHouse/pull/87542) ([Vitaly Baranov](https://github.com/vitlibar)).
#### Bug Fix (user-visible misbehavior in an official stable release)
* Fixed GeoParquet causing client protocol errors. [#84020](https://github.com/ClickHouse/ClickHouse/pull/84020) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix resolving host-dependent functions like shardNum() in subqueries on initiator node. [#84409](https://github.com/ClickHouse/ClickHouse/pull/84409) ([Eduard Karacharov](https://github.com/korowa)).
* Fixed incorrect handling of pre-epoch dates with fractional seconds in various date time related functions, such as `parseDateTime64BestEffort`, `change{Year,Month,Day}` and `makeDateTime64`. Previously the subsecond part was substracted from seconds instead of adding them. For example `parseDateTime64BestEffort('1969-01-01 00:00:00.468')` was returning `1968-12-31 23:59:59.532` instead of `1969-01-01 00:00:00.468`. [#85396](https://github.com/ClickHouse/ClickHouse/pull/85396) ([xiaohuanlin](https://github.com/xiaohuanlin)).
* Fix ALTER COLUMN IF EXISTS commands failing when column state changes within the same ALTER statement. Commands like DROP COLUMN IF EXISTS, MODIFY COLUMN IF EXISTS, COMMENT COLUMN IF EXISTS, and RENAME COLUMN IF EXISTS now properly handle cases where a column is deleted by a previous command in the same statement. [#86046](https://github.com/ClickHouse/ClickHouse/pull/86046) ([xiaohuanlin](https://github.com/xiaohuanlin)).
* Fix inferring Date/DateTime/DateTime64 on dates that are out of supported range. [#86184](https://github.com/ClickHouse/ClickHouse/pull/86184) ([Pavel Kruglov](https://github.com/Avogar)).
* Fixes a crash where some valid user-submitted data to an `AggregateFunction(quantileDD)` column could cause merges to recurse infinitely. [#86560](https://github.com/ClickHouse/ClickHouse/pull/86560) ([Raphaël Thériault](https://github.com/raphael-theriault-swi)).
* Support JSON/Dynamic types in table created as `cluster` table function. [#86821](https://github.com/ClickHouse/ClickHouse/pull/86821) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix result of function calculated in CTE being non-deterministic in the query. [#86967](https://github.com/ClickHouse/ClickHouse/pull/86967) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Fix LOGICAL\_ERROR in EXPLAIN with pointInPolygon on primary key columns. [#86971](https://github.com/ClickHouse/ClickHouse/pull/86971) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix data lake tables with a percent-encoded sequence in the name. Closes [#86626](https://github.com/ClickHouse/ClickHouse/issues/86626). [#87020](https://github.com/ClickHouse/ClickHouse/pull/87020) ([Anton Ivashkin](https://github.com/ianton-ru)).
* Fix incorrect `IS NULL` behavior on nullable columns in `OUTER JOIN` with `optimize_functions_to_subcolumns`, close [#78625](https://github.com/ClickHouse/ClickHouse/issues/78625). [#87058](https://github.com/ClickHouse/ClickHouse/pull/87058) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fixed incorrect accounting of temporary data deallocations in `max_temporary_data_on_disk_size` limit tracking, close [#87118](https://github.com/ClickHouse/ClickHouse/issues/87118). [#87140](https://github.com/ClickHouse/ClickHouse/pull/87140) ([JIaQi](https://github.com/JiaQiTang98)).
* The function checkHeaders is now properly validating the provided headers and reject forbidden headers. Original author: Michael Anastasakis (@michael-anastasakis). [#87172](https://github.com/ClickHouse/ClickHouse/pull/87172) ([Raúl Marín](https://github.com/Algunenano)).
* Makes the same behaviour of `toDate` and `toDate32` for all numeric types. Fixes Date32 underflow check during cast from int16. [#87176](https://github.com/ClickHouse/ClickHouse/pull/87176) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Fix logical error with parallel replicas for queries with multiple JOINs, with RIGHT JOIN after LEFT/INNER JOIN in particular. [#87178](https://github.com/ClickHouse/ClickHouse/pull/87178) ([Igor Nikonov](https://github.com/devcrafter)).
* Respect setting `input_format_try_infer_variants` in schema inference cache. [#87180](https://github.com/ClickHouse/ClickHouse/pull/87180) ([Pavel Kruglov](https://github.com/Avogar)).
* Make pathStartsWith only match paths under the prefix. [#87181](https://github.com/ClickHouse/ClickHouse/pull/87181) ([Raúl Marín](https://github.com/Algunenano)).
* Fixed logical errors in `_row_number` virtual column and iceberg positioned deletes. [#87220](https://github.com/ClickHouse/ClickHouse/pull/87220) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix "Too large size passed to allocator" `LOGICAL_ERROR` in `JOIN` due to mixed const and non-const blocks. [#87231](https://github.com/ClickHouse/ClickHouse/pull/87231) ([Azat Khuzhin](https://github.com/azat)).
* Fixed lightweight updates with subqueries that read from another `MergeTree` tables. [#87285](https://github.com/ClickHouse/ClickHouse/pull/87285) ([Anton Popov](https://github.com/CurtizJ)).
* Fixed move-to-prewhere optimization, which did not work in the presence of row policy. Continuation of [#85118](https://github.com/ClickHouse/ClickHouse/issues/85118). Closes [#69777](https://github.com/ClickHouse/ClickHouse/issues/69777). Closes [#83748](https://github.com/ClickHouse/ClickHouse/issues/83748). [#87303](https://github.com/ClickHouse/ClickHouse/pull/87303) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fixed applying patches to columns with default expression that are missing in data parts. [#87347](https://github.com/ClickHouse/ClickHouse/pull/87347) ([Anton Popov](https://github.com/CurtizJ)).
* Fixed segmentation fault when using duplicate partition field names in MergeTree tables. [#87365](https://github.com/ClickHouse/ClickHouse/pull/87365) ([xiaohuanlin](https://github.com/xiaohuanlin)).
* Fix EmbeddedRocksDB upgrade. [#87392](https://github.com/ClickHouse/ClickHouse/pull/87392) ([Raúl Marín](https://github.com/Algunenano)).
* Fixed direct reading from the text index on object storage. [#87399](https://github.com/ClickHouse/ClickHouse/pull/87399) ([Anton Popov](https://github.com/CurtizJ)).
* Prevent privilege with non-existent engine to be created. [#87419](https://github.com/ClickHouse/ClickHouse/pull/87419) ([Jitendra](https://github.com/jitendra1411)).
* Ignore only not found errors for `s3_plain_rewritable` (which may lead to all sort of troubles). [#87426](https://github.com/ClickHouse/ClickHouse/pull/87426) ([Azat Khuzhin](https://github.com/azat)).
* Fix dictionaries with YTSaurus source and \*range\_hashed layouts. [#87490](https://github.com/ClickHouse/ClickHouse/pull/87490) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* Fix creating an array of empty tuples. [#87520](https://github.com/ClickHouse/ClickHouse/pull/87520) ([Pavel Kruglov](https://github.com/Avogar)).
* Check for illegal columns during temporary table creation. [#87524](https://github.com/ClickHouse/ClickHouse/pull/87524) ([Pavel Kruglov](https://github.com/Avogar)).
* Never put hive partition columns in the format header. Fixes [#87515](https://github.com/ClickHouse/ClickHouse/issues/87515). [#87528](https://github.com/ClickHouse/ClickHouse/pull/87528) ([Arthur Passos](https://github.com/arthurpassos)).
* Fix preparing reading from format in DeltaLake when text format is used. [#87529](https://github.com/ClickHouse/ClickHouse/pull/87529) ([Pavel Kruglov](https://github.com/Avogar)).
* Fixes access validation on select and insert for Buffer tables. [#87545](https://github.com/ClickHouse/ClickHouse/pull/87545) ([pufit](https://github.com/pufit)).
* Disallow creating data skipping index for S3 table. [#87554](https://github.com/ClickHouse/ClickHouse/pull/87554) ([Bharat Nallan](https://github.com/bharatnc)).
* Avoid leaking of tracked memory for async logging (can have a significant drift, for 10 hours, \~100GiB) and text\_log (almost same drift is possible). [#87584](https://github.com/ClickHouse/ClickHouse/pull/87584) ([Azat Khuzhin](https://github.com/azat)).
* Fixed a bug that might lead to overriding global server settings with SELECT settings of a View or Materialized View, if this view was dropped asynchronously and the server was restarted before finishing background cleanup. [#87603](https://github.com/ClickHouse/ClickHouse/pull/87603) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Exclude userspace page cache bytes (if possible) when computing memory overload warning. [#87610](https://github.com/ClickHouse/ClickHouse/pull/87610) ([Bharat Nallan](https://github.com/bharatnc)).
* Fix a bug when incorrect type order during CSV deserialization led to the `LOGICAL_ERROR`. [#87622](https://github.com/ClickHouse/ClickHouse/pull/87622) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Fix incorrect handling of `command_read_timeout` for executable dictionaries. [#87627](https://github.com/ClickHouse/ClickHouse/pull/87627) ([Azat Khuzhin](https://github.com/azat)).
* Fixed incorrect SELECT \* REPLACE behavior in WHERE clause with new analyzer when filtering on replaced columns. [#87630](https://github.com/ClickHouse/ClickHouse/pull/87630) ([xiaohuanlin](https://github.com/xiaohuanlin)).
* Fixed two-level aggregation when using `Merge` over `Distributed`. [#87687](https://github.com/ClickHouse/ClickHouse/pull/87687) ([c-end](https://github.com/c-end)).
* Fix the generation of the output block in the HashJoin algorithm when the right row list is not used. Fixes [#87401](https://github.com/ClickHouse/ClickHouse/issues/87401). [#87699](https://github.com/ClickHouse/ClickHouse/pull/87699) ([Dmitry Novik](https://github.com/novikd)).
* Parallel replicas read mode could be chosen incorrectly if there are no data to read after applying index analysis. Closes [#87653](https://github.com/ClickHouse/ClickHouse/issues/87653). [#87700](https://github.com/ClickHouse/ClickHouse/pull/87700) ([zoomxi](https://github.com/zoomxi)).
* Fix handling of `timestamp` / `timestamptz` columns in Glue. [#87733](https://github.com/ClickHouse/ClickHouse/pull/87733) ([Andrey Zvonov](https://github.com/zvonand)).
* This closes [#86587](https://github.com/ClickHouse/ClickHouse/issues/86587). [#87761](https://github.com/ClickHouse/ClickHouse/pull/87761) ([scanhex12](https://github.com/scanhex12)).
* Fix writing boolean values in PostgreSQL interface. [#87762](https://github.com/ClickHouse/ClickHouse/pull/87762) ([Artem Yurov](https://github.com/ArtemYurov)).
* Fix unknown table error in insert select query with CTE, [#85368](https://github.com/ClickHouse/ClickHouse/issues/85368). [#87789](https://github.com/ClickHouse/ClickHouse/pull/87789) ([Guang Zhao](https://github.com/zheguang)).
* Fix reading null map subcolumn from Variants that cannot be inside Nullable. [#87798](https://github.com/ClickHouse/ClickHouse/pull/87798) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix handling error when failing to drop the database completely on the cluster on the secondary node. [#87802](https://github.com/ClickHouse/ClickHouse/pull/87802) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Fix several skip indices bugs. [#87817](https://github.com/ClickHouse/ClickHouse/pull/87817) ([Raúl Marín](https://github.com/Algunenano)).
* In AzureBlobStorage, updated to try native copy first and go to read & write on 'Unauthroized' error (In AzureBlobStorage, if storage accounts are different for source & destination we get 'Unauthorized' error). And fix applying "use\_native\_copy" when endpoint is defined in configuration. [#87826](https://github.com/ClickHouse/ClickHouse/pull/87826) ([Smita Kulkarni](https://github.com/SmitaRKulkarni)).
* ClickHouse crashes if ArrowStream file has non-unique dictionary. [#87863](https://github.com/ClickHouse/ClickHouse/pull/87863) ([Ilya Golshtein](https://github.com/ilejn)).
* Fix fatal using approx\_top\_k and finalizeAggregation. [#87892](https://github.com/ClickHouse/ClickHouse/pull/87892) ([Jitendra](https://github.com/jitendra1411)).
* Fix merge with projections when the last block is empty. [#87928](https://github.com/ClickHouse/ClickHouse/pull/87928) ([Raúl Marín](https://github.com/Algunenano)).
* Don't remove injective functions from GROUP BY if arguments types are not allowed in GROUP BY. [#87958](https://github.com/ClickHouse/ClickHouse/pull/87958) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix for incorrect granules/partitions elimination for datetime-based keys, when using `session_timezone` setting in queries. [#87987](https://github.com/ClickHouse/ClickHouse/pull/87987) ([Eduard Karacharov](https://github.com/korowa)).
* Returns affected rows count after query in PostgreSQL Interface. [#87990](https://github.com/ClickHouse/ClickHouse/pull/87990) ([Artem Yurov](https://github.com/ArtemYurov)).
* Restrics using of filter pushdown for PASTE JOIN because it can cause incorrect results. [#88078](https://github.com/ClickHouse/ClickHouse/pull/88078) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Applies URI normalization before evaluation for the grants check introduced by [https://github.com/ClickHouse/ClickHouse/pull/84503](https://github.com/ClickHouse/ClickHouse/pull/84503). [#88089](https://github.com/ClickHouse/ClickHouse/pull/88089) ([pufit](https://github.com/pufit)).
* Fix logical error when ARRAY JOIN COLUMNS() matches no columns in new analyzer. [#88091](https://github.com/ClickHouse/ClickHouse/pull/88091) ([xiaohuanlin](https://github.com/xiaohuanlin)).
* Fix "High ClickHouse memory usage" warning (exclude page cache). [#88092](https://github.com/ClickHouse/ClickHouse/pull/88092) ([Azat Khuzhin](https://github.com/azat)).
* Fixed possible data corruption in `MergeTree` tables with set column `TTL`. [#88095](https://github.com/ClickHouse/ClickHouse/pull/88095) ([Anton Popov](https://github.com/CurtizJ)).
* Fix possible uncaught exception while reading `system.tables` with invalid tables in external databases (`PostgreSQL`/`SQLite`/...) attached. [#88105](https://github.com/ClickHouse/ClickHouse/pull/88105) ([Azat Khuzhin](https://github.com/azat)).
* Fixed crash in `mortonEncode` and `hilbertEncode` functions when called with empty tuple argument. [#88110](https://github.com/ClickHouse/ClickHouse/pull/88110) ([xiaohuanlin](https://github.com/xiaohuanlin)).
* Now `ON CLUSTER` queries will take less time in case of inactive replicas in cluster. [#88153](https://github.com/ClickHouse/ClickHouse/pull/88153) ([alesapin](https://github.com/alesapin)).
* Now DDL worker cleanup outdated hosts from replicas set. It will reduce amount of stored metadata in ZooKeeper. [#88154](https://github.com/ClickHouse/ClickHouse/pull/88154) ([alesapin](https://github.com/alesapin)).
* Fix running ClickHouse w/o cgroups (accidentally cgroups became a requirement for asynchronous metrics). [#88164](https://github.com/ClickHouse/ClickHouse/pull/88164) ([Azat Khuzhin](https://github.com/azat)).
* Do proper undo of the move directory operation in case of error. We need to rewrite all `prefix.path` objects changed during the execution, not only the root one. [#88198](https://github.com/ClickHouse/ClickHouse/pull/88198) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Fixed propagation of `is_shared` flag in `ColumnLowCardinality`. It may lead to a wrong group-by result if a new value is inserted in a column after hash values are already pre-calculated and cached in the `ReverseIndex`. [#88213](https://github.com/ClickHouse/ClickHouse/pull/88213) ([Nikita Taranov](https://github.com/nickitat)).
* Fixes a workload setting `max_cpu_share`. Now it can be used without `max_cpus` workload setting being set. [#88217](https://github.com/ClickHouse/ClickHouse/pull/88217) ([Neerav](https://github.com/neeravsalaria)).
* Fix bug that very heavy mutations with subqueries could stuck in prepare stage. Now it's possible to stop these mutations with `SYSTEM STOP MERGES`. [#88241](https://github.com/ClickHouse/ClickHouse/pull/88241) ([alesapin](https://github.com/alesapin)).
* Now correlated subqueries will work with object storages. [#88290](https://github.com/ClickHouse/ClickHouse/pull/88290) ([alesapin](https://github.com/alesapin)).
* Avoid trying to initialize DataLake databases while accessing `system.projections` and `system.data_skipping_indices`. [#88330](https://github.com/ClickHouse/ClickHouse/pull/88330) ([Azat Khuzhin](https://github.com/azat)).
* Now datalakes catalogs will be shown in system introspection tables only if `show_data_lake_catalogs_in_system_tables` explicitly enabled. [#88341](https://github.com/ClickHouse/ClickHouse/pull/88341) ([alesapin](https://github.com/alesapin)).
* Fixed DatabaseReplicated to respect `interserver_http_host` configuration. [#88378](https://github.com/ClickHouse/ClickHouse/pull/88378) ([xiaohuanlin](https://github.com/xiaohuanlin)).
* Positional arguments are now explicitly disabled in the context of defining Projections, as they are not sensible in this internal query stage. This fixes [#48604](https://github.com/ClickHouse/ClickHouse/issues/48604). [#88380](https://github.com/ClickHouse/ClickHouse/pull/88380) ([Amos Bird](https://github.com/amosbird)).
* Fix quadratic complexity in the `countMatches` function. Closes [#88400](https://github.com/ClickHouse/ClickHouse/issues/88400). [#88401](https://github.com/ClickHouse/ClickHouse/pull/88401) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Make `ALTER COLUMN ... COMMENT` commands for KeeperMap tables replicated so they are committed to Replicated database metadata and propagated across all replicas. Closes [#88077](https://github.com/ClickHouse/ClickHouse/issues/88077). [#88408](https://github.com/ClickHouse/ClickHouse/pull/88408) ([Eduard Karacharov](https://github.com/korowa)).
* Fix a case of false cyclic dependency with Materialized Views in Database Replicated, which prevented new replicas from being added to the database. [#88423](https://github.com/ClickHouse/ClickHouse/pull/88423) ([Nikolay Degterinsky](https://github.com/evillique)).
* Fix aggregation of sparse columns when `group_by_overflow_mode` is set to `any`. [#88440](https://github.com/ClickHouse/ClickHouse/pull/88440) ([Eduard Karacharov](https://github.com/korowa)).
* Fix "column not found" error when using `query_plan_use_logical_join_step=0` with multiple FULL JOIN USING clauses. Closes [#88103](https://github.com/ClickHouse/ClickHouse/issues/88103). [#88473](https://github.com/ClickHouse/ClickHouse/pull/88473) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Big clusters with node numbers > 10 have a high probability of failing the restore with error `[941] 67c45db4-4df4-4879-87c5-25b8d1e0d414 : RestoreCoordinationOnCluster The version of node /clickhouse/backups/restore-7c551a77-bd76-404c-bad0-3213618ac58e/stage/num_hosts changed (attempt #9), will try again`. The `num_hosts` node is overwritten by many hosts at the same time. The fix makes the setting to control attempts dynamic. Closes [#87721](https://github.com/ClickHouse/ClickHouse/issues/87721). [#88484](https://github.com/ClickHouse/ClickHouse/pull/88484) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
* This PR just for making compatibility to 23.8 and before, The compatibility issue was introduced by this PR: [https://github.com/ClickHouse/ClickHouse/pull/54240](https://github.com/ClickHouse/ClickHouse/pull/54240) This SQL will fail with `enable_analyzer=0` (before 23.8, it's ok). [#88491](https://github.com/ClickHouse/ClickHouse/pull/88491) ([JIaQi](https://github.com/JiaQiTang98)).
* Fix UBSAN integer overflow in `accurateCast` error message when converting large values to DateTime. [#88520](https://github.com/ClickHouse/ClickHouse/pull/88520) ([xiaohuanlin](https://github.com/xiaohuanlin)).
* Fix coalescing merge tree for tuple types. This closes [#88469](https://github.com/ClickHouse/ClickHouse/issues/88469). [#88526](https://github.com/ClickHouse/ClickHouse/pull/88526) ([scanhex12](https://github.com/scanhex12)).
* Forbid deletes for `iceberg_format_version=1`. This closes [#88444](https://github.com/ClickHouse/ClickHouse/issues/88444). [#88532](https://github.com/ClickHouse/ClickHouse/pull/88532) ([scanhex12](https://github.com/scanhex12)).
* This patch fixes the move operation of `plain-rewritable` disks for folders of arbitrary depth. [#88586](https://github.com/ClickHouse/ClickHouse/pull/88586) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Fix SQL SECURITY DEFINER with \*cluster functions. [#88588](https://github.com/ClickHouse/ClickHouse/pull/88588) ([Julian Maicher](https://github.com/jmaicher)).
* Fix potential crash caused by concurrent mutation of underlying const PREWHERE columns. [#88605](https://github.com/ClickHouse/ClickHouse/pull/88605) ([Azat Khuzhin](https://github.com/azat)).
* Fixed reading from the text index and enabled query condition cache (with enabled settings `use_skip_indexes_on_data_read` and `use_query_condition_cache`). [#88660](https://github.com/ClickHouse/ClickHouse/pull/88660) ([Anton Popov](https://github.com/CurtizJ)).
* A `Poco::TimeoutException` exception thrown from `Poco::Net::HTTPChunkedStreamBuf::readFromDevice` leads to a crash with SIGABRT. [#88668](https://github.com/ClickHouse/ClickHouse/pull/88668) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Backported in [#88910](https://github.com/ClickHouse/ClickHouse/issues/88910): After recovering, a Replicated database replica might get stuck for a long time printing messages like `Failed to marked query-0004647339 as finished (finished=No node, synced=No node)`, it's fixed. [#88671](https://github.com/ClickHouse/ClickHouse/pull/88671) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Fix appending to `system.zookeeper_connection_log` in case ClickHouse connects for the first time after config reload. [#88728](https://github.com/ClickHouse/ClickHouse/pull/88728) ([Antonio Andelic](https://github.com/antonio2368)).
* Fixed a bug where converting DateTime64 to Date with `date_time_overflow_behavior = 'saturate'` could lead to incorrect results for out-of-range values when working with time zones. [#88737](https://github.com/ClickHouse/ClickHouse/pull/88737) ([Manuel](https://github.com/raimannma)).
* Nth attempt to fix "having zero bytes error" with s3 table engine with enabled cache. [#88740](https://github.com/ClickHouse/ClickHouse/pull/88740) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fixes access validation on select for `loop` table function. [#88802](https://github.com/ClickHouse/ClickHouse/pull/88802) ([pufit](https://github.com/pufit)).
* Catch exceptions when async logging fails to prevent program aborts. [#88814](https://github.com/ClickHouse/ClickHouse/pull/88814) ([Raúl Marín](https://github.com/Algunenano)).
* Backported in [#89060](https://github.com/ClickHouse/ClickHouse/issues/89060): Fix `top_k` to respect the threshold parameter when called with a single argument. Closes [#88757](https://github.com/ClickHouse/ClickHouse/issues/88757). [#88867](https://github.com/ClickHouse/ClickHouse/pull/88867) ([Manuel](https://github.com/raimannma)).
* Backported in [#88944](https://github.com/ClickHouse/ClickHouse/issues/88944): Fix bug in the function `reverseUTF8`. In previous versions, it mistakenly reversed the bytes of UTF-8 code points of length 4. This closes [#88913](https://github.com/ClickHouse/ClickHouse/issues/88913). [#88914](https://github.com/ClickHouse/ClickHouse/pull/88914) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Backported in [#88980](https://github.com/ClickHouse/ClickHouse/issues/88980): Do not check access `SET DEFINER :definer` when creating a view with SQL SECURITY DEFINER. [#88968](https://github.com/ClickHouse/ClickHouse/pull/88968) ([pufit](https://github.com/pufit)).
* Backported in [#89058](https://github.com/ClickHouse/ClickHouse/issues/89058): Fixed `LOGICAL_ERROR` in `L2DistanceTransposed(vec1, vec2, p)` where the optimisation for partial `QBit` reading incorrectly removed `Nullable` from the return type when `p` was `Nullable`. [#88974](https://github.com/ClickHouse/ClickHouse/pull/88974) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Backported in [#89167](https://github.com/ClickHouse/ClickHouse/issues/89167): Fix crash in unknown catalog type. Resolves [#88819](https://github.com/ClickHouse/ClickHouse/issues/88819). [#88987](https://github.com/ClickHouse/ClickHouse/pull/88987) ([scanhex12](https://github.com/scanhex12)).
* Backported in [#89028](https://github.com/ClickHouse/ClickHouse/issues/89028): Fixed performance degradation in analysis of skipping indexes. [#89004](https://github.com/ClickHouse/ClickHouse/pull/89004) ([Anton Popov](https://github.com/CurtizJ)).
#### Build/Testing/Packaging Improvement
* Use `postgres` library version 18.0. [#87647](https://github.com/ClickHouse/ClickHouse/pull/87647) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Enable ICU for FreeBSD. [#87891](https://github.com/ClickHouse/ClickHouse/pull/87891) ([Raúl Marín](https://github.com/Algunenano)).
* Use SSE 4.2 when we use dynamic dispatch to SSE 4.2 and not SSE 4. [#88029](https://github.com/ClickHouse/ClickHouse/pull/88029) ([Raúl Marín](https://github.com/Algunenano)).
* Don't require `NO_ARMV81_OR_HIGHER` flag if `Speculative Store Bypass Safe` is unavailable. [#88051](https://github.com/ClickHouse/ClickHouse/pull/88051) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* When ClickHouse is built with `ENABLE_LIBFIU=OFF`, failpoint-related functions become no-ops and cannot impact performance anymore. `SYSTEM ENABLE/DISABLE FAILPOINT` queries return a `SUPPORT_IS_DISABLED` error in that case. [#88184](https://github.com/ClickHouse/ClickHouse/pull/88184) ([c-end](https://github.com/c-end)).
ClickHouse release 25.9, 2025-09-25
#### Backward Incompatible Change
* Disable nonsensical binary operations with IPv4/IPv6: Plus / minus of a IPv4/IPv6 with a non-integer type is disabled. Before it would allow operations with floating types and throw logical errors with some other types (such as DateTime). [#86336](https://github.com/ClickHouse/ClickHouse/pull/86336) ([Raúl Marín](https://github.com/Algunenano)).
* Deprecate setting `allow_dynamic_metadata_for_data_lakes`. Now all iceberg tables try to fetch up-to-date table schema from storage before executing of each query. [#86366](https://github.com/ClickHouse/ClickHouse/pull/86366) ([Daniil Ivanik](https://github.com/divanik)).
* Changed resolving of the coalesced column from `OUTER JOIN ... USING` clause to be more consistent: previously, when selecting both the USING column and qualified columns (`a, t1.a, t2.a`) in a OUTER JOIN, the USING column would incorrectly be resolved to `t1.a`, showing 0/NULL for rows from the right table with no left match. Now identifiers from USING clause are always resolved to the coalesced column, while qualified identifiers resolve to the non-coalesced columns, regardless of which other identifiers are present in the query. For example: \`\`\`sql SELECT a, t1.a, t2.a FROM (SELECT 1 as a WHERE 0) t1 FULL JOIN (SELECT 2 as a) t2 USING (a) -- Before: a=0, t1.a=0, t2.a=2 (incorrect - 'a' resolved to t1.a) -- After: a=2, t1.a=0, t2.a=2 (correct - 'a' is coalesced). [#80848](https://github.com/ClickHouse/ClickHouse/pull/80848) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Increase replicated deduplication window up to 10000. This is fully compatible, but we can imagine scenarios when this change could lead to high resource consumption in the presence of a large number of tables. [#86820](https://github.com/ClickHouse/ClickHouse/pull/86820) ([Sema Checherinda](https://github.com/CheSema)).
#### New Feature
* You can now use NATS JetStream to consume messages by specifying the new settings of `nats_stream` and `nats_consumer` for the NATS engine. [#84799](https://github.com/ClickHouse/ClickHouse/pull/84799) ([Dmitry Novikov](https://github.com/dmitry-sles-novikov)).
* Added support for authentication and SSL in the `arrowFlight` table function. [#87120](https://github.com/ClickHouse/ClickHouse/pull/87120) ([Vitaly Baranov](https://github.com/vitlibar)).
* Add new parameter to `S3` table engine and `s3` table function named `storage_class_name` which allows to specify intelligent tiring supported by AWS. Supported both in key-value format and in positional (deprecated) format). [#87122](https://github.com/ClickHouse/ClickHouse/pull/87122) ([alesapin](https://github.com/alesapin)).
* `ALTER UPDATE` for Iceberg table engine. [#86059](https://github.com/ClickHouse/ClickHouse/pull/86059) ([scanhex12](https://github.com/scanhex12)).
* Add system table `iceberg_metadata_log` to retrieve Iceberg metadata files during SELECT statements. [#86152](https://github.com/ClickHouse/ClickHouse/pull/86152) ([scanhex12](https://github.com/scanhex12)).
* `Iceberg` and `DeltaLake` tables support custom disk configuration via storage level setting `disk`. [#86778](https://github.com/ClickHouse/ClickHouse/pull/86778) ([scanhex12](https://github.com/scanhex12)).
* Support Azure for data lakes disks. [#87173](https://github.com/ClickHouse/ClickHouse/pull/87173) ([scanhex12](https://github.com/scanhex12)).
* Support `Unity` catalog on top of Azure blob storage. [#80013](https://github.com/ClickHouse/ClickHouse/pull/80013) ([Smita Kulkarni](https://github.com/SmitaRKulkarni)).
* Support more formats (`ORC`, `Avro`) in `Iceberg` writes. This closes [#86179](https://github.com/ClickHouse/ClickHouse/issues/86179). [#87277](https://github.com/ClickHouse/ClickHouse/pull/87277) ([scanhex12](https://github.com/scanhex12)).
* Add a new system table `database_replicas` with information about database replicas. [#83408](https://github.com/ClickHouse/ClickHouse/pull/83408) ([Konstantin Morozov](https://github.com/k-morozov)).
* Added function `arrayExcept` that subtracts one array as a set from another. [#82368](https://github.com/ClickHouse/ClickHouse/pull/82368) ([Joanna Hulboj](https://github.com/jh0x)).
* Adds a new `system.aggregated_zookeeper_log` table. The table contains statistics (e.g. number of operations, average latency, errors) of ZooKeeper operations grouped by session id, parent path and operation type, and periodically flushed to disk. [#85102](https://github.com/ClickHouse/ClickHouse/pull/85102) [#87208](https://github.com/ClickHouse/ClickHouse/pull/87208) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* A new function, `isValidASCII`. Returns 1 if the input string or FixedString contains only ASCII bytes (0x00–0x7F) else 0. Closes [#85377](https://github.com/ClickHouse/ClickHouse/issues/85377). ... [#85786](https://github.com/ClickHouse/ClickHouse/pull/85786) ([rajat mohan](https://github.com/rajatmohan22)).
* Boolean settings can be specified without arguments, e.g., `SET use_query_cache;`, which is equivalent to setting it to true. [#85800](https://github.com/ClickHouse/ClickHouse/pull/85800) ([thraeka](https://github.com/thraeka)).
* New configuration options: `logger.startupLevel` & `logger.shutdownLevel` allow for overriding the log level during the startup & shutdown of Clickhouse respectively. [#85967](https://github.com/ClickHouse/ClickHouse/pull/85967) ([Lennard Eijsackers](https://github.com/Blokje5)).
* Aggregate functions `timeSeriesChangesToGrid` and `timeSeriesResetsToGrid`. Behaves similarly to `timeSeriesRateToGrid`, accepting parameters for start timestamp, end timestamp, step, and look back window, as well as two arguments for the timestamps and values, but requiring at least 1 sample per window instead of 2. Calculates a PromQL `changes`/`resets`, counting the number of times the sample value changes or decreases in the specified window for each timestamp in the time grid defined by the parameters. The return type is `Array(Nullable(Float64))`. [#86010](https://github.com/ClickHouse/ClickHouse/pull/86010) ([Stephen Chi](https://github.com/stephchi0)).
* Allows users to create temporary views with a similar syntax to temporary tables (`CREATE TEMPORARY VIEW`). [#86432](https://github.com/ClickHouse/ClickHouse/pull/86432) ([Aly Kafoury](https://github.com/AlyHKafoury)).
* Add warnings for CPU and memory usage to the `system.warnings` table. [#86838](https://github.com/ClickHouse/ClickHouse/pull/86838) ([Bharat Nallan](https://github.com/bharatnc)).
* Support the `oneof` indicator in `Protobuf` inputs. A special column may be used to indicate the presence of part of oneof. If a message contains [oneof](https://protobuf.dev/programming-guides/proto3/#oneof) and `input_format_protobuf_oneof_presence` is set, ClickHouse fills column that indicates which field of oneof was found. [#82885](https://github.com/ClickHouse/ClickHouse/pull/82885) ([Ilya Golshtein](https://github.com/ilejn)).
* Improve allocation profiling based on jemalloc's internal tooling. Global jemalloc profiler can now be enabled with config `jemalloc_enable_global_profiler`. Sampled global allocations and deallocations can be stored in `system.trace_log` under `JemallocSample` type by enabling config `jemalloc_collect_global_profile_samples_in_trace_log`. Jemalloc profiling can now be enabled for each query independently using setting `jemalloc_enable_profiler`. Storing samples in `system.trace_log` can be controlled per query using setting `jemalloc_collect_profile_samples_in_trace_log`. Update jemalloc to newer version. [#85438](https://github.com/ClickHouse/ClickHouse/pull/85438) ([Antonio Andelic](https://github.com/antonio2368)).
* A new setting to delete files on dropping Iceberg tables. This closes [#86211](https://github.com/ClickHouse/ClickHouse/issues/86211). [#86501](https://github.com/ClickHouse/ClickHouse/pull/86501) ([scanhex12](https://github.com/scanhex12)).
#### Experimental Feature
* The inverted text index was reworked from scratch to be scalable for datasets that don't fit into RAM. [#86485](https://github.com/ClickHouse/ClickHouse/pull/86485) ([Anton Popov](https://github.com/CurtizJ)).
* Join reordering now uses statistics. The feature can be enabled by setting `allow_statistics_optimize = 1` and `query_plan_optimize_join_order_limit = 10`. [#86822](https://github.com/ClickHouse/ClickHouse/pull/86822) ([Han Fei](https://github.com/hanfei1991)).
* Support `alter table ... materialize statistics all` will materialize all the statistics of a table. [#87197](https://github.com/ClickHouse/ClickHouse/pull/87197) ([Han Fei](https://github.com/hanfei1991)).
#### Performance Improvement
* Support filtering data parts using skip indexes during reading to reduce unnecessary index reads. Controlled by the new setting `use_skip_indexes_on_data_read` (disabled by default). This addresses [#75774](https://github.com/ClickHouse/ClickHouse/issues/75774). This includes some common groundwork shared with [#81021](https://github.com/ClickHouse/ClickHouse/issues/81021). [#81526](https://github.com/ClickHouse/ClickHouse/pull/81526) ([Amos Bird](https://github.com/amosbird)).
* Added JOIN order optimization that can automatically reorder JOINs for better performance (controlled by `query_plan_optimize_join_order_limit` setting). Note that the join order optimization currently has limited statistics support and primarily relies on row count estimates from storage engines - more sophisticated statistics collection and cardinality estimation will be added in future releases. **If you encounter issues with JOIN queries after upgrading**, you can temporarily disable the new implementation by setting `SET query_plan_use_new_logical_join_step = 0` and report the issue for investigation. **Note about resolution of identifiers from USING clause**: Changed resolving of the coalesced column from `OUTER JOIN ... USING` clause to be more consistent: previously, when selecting both the USING column and qualified columns (`a, t1.a, t2.a`) in a OUTER JOIN, the USING column would incorrectly be resolved to `t1.a`, showing 0/NULL for rows from the right table with no left match. Now identifiers from USING clause are always resolved to the coalesced column, while qualified identifiers resolve to the non-coalesced columns, regardless of which other identifiers are present in the query. For example: \`\`\`sql SELECT a, t1.a, t2.a FROM (SELECT 1 as a WHERE 0) t1 FULL JOIN (SELECT 2 as a) t2 USING (a) -- Before: a=0, t1.a=0, t2.a=2 (incorrect - 'a' resolved to t1.a) -- After: a=2, t1.a=0, t2.a=2 (correct - 'a' is coalesced). [#80848](https://github.com/ClickHouse/ClickHouse/pull/80848) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Distributed `INSERT SELECT` for data lakes. [#86783](https://github.com/ClickHouse/ClickHouse/pull/86783) ([scanhex12](https://github.com/scanhex12)).
* Improve PREWHERE optimization for conditions like `func(primary_column) = 'xx'` and `column in (xxx)`. [#85529](https://github.com/ClickHouse/ClickHouse/pull/85529) ([李扬](https://github.com/taiyang-li)).
* Implemented rewriting of JOIN: 1. Convert `LEFT ANY JOIN` and `RIGHT ANY JOIN` to `SEMI`/`ANTI` JOIN if the filter condition is always false for matched or non-matched rows. This optimization is controlled by a new setting `query_plan_convert_any_join_to_semi_or_anti_join`. 2. Convert `FULL ALL JOIN` to `LEFT ALL` or `RIGHT ALL` JOIN if the filter condition is always false for non-matched rows from one side. [#86028](https://github.com/ClickHouse/ClickHouse/pull/86028) ([Dmitry Novik](https://github.com/novikd)).
* Improved performance of vertical merges after executing a lightweight delete. [#86169](https://github.com/ClickHouse/ClickHouse/pull/86169) ([Anton Popov](https://github.com/CurtizJ)).
* `HashJoin` performance optimised slightly in the case of `LEFT/RIGHT` join having a lot of unmatched rows. [#86312](https://github.com/ClickHouse/ClickHouse/pull/86312) ([Nikita Taranov](https://github.com/nickitat)).
* Radix sort: help the compiler use SIMD and do better prefetching. Uses dynamic dispatch to use software prefetching with Intel CPUs only. Continues the work by @taiyang-li in [https://github.com/ClickHouse/ClickHouse/pull/77029](https://github.com/ClickHouse/ClickHouse/pull/77029). [#86378](https://github.com/ClickHouse/ClickHouse/pull/86378) ([Raúl Marín](https://github.com/Algunenano)).
* Improves performance of short queries with lots of parts in tables (by optimizing `MarkRanges` by using `devector` over `deque`). [#86933](https://github.com/ClickHouse/ClickHouse/pull/86933) ([Azat Khuzhin](https://github.com/azat)).
* Improved performance of applying patch parts in the join mode. [#87094](https://github.com/ClickHouse/ClickHouse/pull/87094) ([Anton Popov](https://github.com/CurtizJ)).
* Added setting `query_condition_cache_selectivity_threshold` (default value: 1.0) which excludes scan results of predicates with low selectivity from insertion into the query condition cache. This allows to reduce the memory consumption of the query condition cache at the cost of a worse cache hit rate. [#86076](https://github.com/ClickHouse/ClickHouse/pull/86076) ([zhongyuankai](https://github.com/zhongyuankai)).
* Reduce memory usage in Iceberg writes. [#86544](https://github.com/ClickHouse/ClickHouse/pull/86544) ([scanhex12](https://github.com/scanhex12)).
#### Improvement
* Support writing multiple data files in Iceberg in a single insertion. Add new settings, `iceberg_insert_max_rows_in_data_file` and `iceberg_insert_max_bytes_in_data_file` to control the limits. [#86275](https://github.com/ClickHouse/ClickHouse/pull/86275) ([scanhex12](https://github.com/scanhex12)).
* Add rows/bytes limit for inserted data files in delta lake. Controlled by settings `delta_lake_insert_max_rows_in_data_file` and `delta_lake_insert_max_bytes_in_data_file`. [#86357](https://github.com/ClickHouse/ClickHouse/pull/86357) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Support more types for partitions in Iceberg writes. This closes [#86206](https://github.com/ClickHouse/ClickHouse/issues/86206). [#86298](https://github.com/ClickHouse/ClickHouse/pull/86298) ([scanhex12](https://github.com/scanhex12)).
* Make S3 retry strategy configurable and make settings of S3 disk can be hot reload if change the config XML file. [#82642](https://github.com/ClickHouse/ClickHouse/pull/82642) ([RinChanNOW](https://github.com/RinChanNOWWW)).
* Improved S3(Azure)Queue table engine to allow it to survive zookeeper connection loss without potential duplicates. Requires enabling S3Queue setting `use_persistent_processing_nodes` (changeable by `ALTER TABLE MODIFY SETTING`). [#85995](https://github.com/ClickHouse/ClickHouse/pull/85995) ([Kseniia Sumarokova](https://github.com/kssenii)).
* You can use query parameters after `TO` when creating a materialized view, for example: `CREATE MATERIALIZED VIEW mv TO {to_table:Identifier} AS SELECT * FROM src_table`. [#84899](https://github.com/ClickHouse/ClickHouse/pull/84899) ([Diskein](https://github.com/Diskein)).
* Give more clear instruction for users when incorrect settings are specified for the `Kafka2` table engine. [#83701](https://github.com/ClickHouse/ClickHouse/pull/83701) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* It's no longer possible to specify time zones for the `Time` type (it didn't make sense). [#84689](https://github.com/ClickHouse/ClickHouse/pull/84689) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Simplified (and avoided some bugs) a logic related to parsing Time/Time64 in the `best_effort` mode. [#84730](https://github.com/ClickHouse/ClickHouse/pull/84730) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Added `deltaLakeAzureCluster` function (similar to `deltaLakeAzure` for the cluster mode) and `deltaLakeS3Cluster` (alias to `deltaLakeCluster`) function. Resolves [#85358](https://github.com/ClickHouse/ClickHouse/issues/85358). [#85547](https://github.com/ClickHouse/ClickHouse/pull/85547) ([Smita Kulkarni](https://github.com/SmitaRKulkarni)).
* Apply `azure_max_single_part_copy_size` setting for normal copy operations in the same way as for backup. [#85767](https://github.com/ClickHouse/ClickHouse/pull/85767) ([Ilya Golshtein](https://github.com/ilejn)).
* Slow down S3 client threads on retryable errors in S3 Object Storage. This extends the previous setting `backup_slow_all_threads_after_retryable_s3_error` to S3 disks and renames it to the more general `s3_slow_all_threads_after_retryable_error`. [#85918](https://github.com/ClickHouse/ClickHouse/pull/85918) ([Julia Kartseva](https://github.com/jkartseva)).
* Mark settings allow\_experimental\_variant/dynamic/json and enable\_variant/dynamic/json as obsolete. Now all three types are enabled unconditionally. [#85934](https://github.com/ClickHouse/ClickHouse/pull/85934) ([Pavel Kruglov](https://github.com/Avogar)).
* Support filtering by complete URL string (`full_url` directive) in `http_handlers` (including schema and host:port). [#86155](https://github.com/ClickHouse/ClickHouse/pull/86155) ([Azat Khuzhin](https://github.com/azat)).
* Add a new setting, `allow_experimental_delta_lake_writes`. [#86180](https://github.com/ClickHouse/ClickHouse/pull/86180) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix detection of systemd in init.d script (fixes "Install packages" check). [#86187](https://github.com/ClickHouse/ClickHouse/pull/86187) ([Azat Khuzhin](https://github.com/azat)).
* Add a new `startup_scripts_failure_reason` dimensional metric. This metric is needed to distinguish between different error types that result in failing startup scripts. In particular, for alerting purposes, we need to distinguish between transient (e.g., `MEMORY_LIMIT_EXCEEDED` or `KEEPER_EXCEPTION`) and non-transient errors. [#86202](https://github.com/ClickHouse/ClickHouse/pull/86202) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Allow to omit `identity` function for partition for Iceberg table. [#86314](https://github.com/ClickHouse/ClickHouse/pull/86314) ([scanhex12](https://github.com/scanhex12)).
* Add ability to enable JSON logging only for specific channel, for this set `logger.formatting.channel` to one of `syslog`/`console`/`errorlog`/`log`. [#86331](https://github.com/ClickHouse/ClickHouse/pull/86331) ([Azat Khuzhin](https://github.com/azat)).
* Allow using native numbers in `WHERE`. They are already allowed to be arguments of logical functions. This simplifies filter-push-down and move-to-prewhere optimizations. [#86390](https://github.com/ClickHouse/ClickHouse/pull/86390) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fixed error in case of executing `SYSTEM DROP REPLICA` against a Catalog with corrupted metadata. [#86391](https://github.com/ClickHouse/ClickHouse/pull/86391) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Add extra retries for disk access check (`skip_access_check = 0`) in Azure because it may be provisioning access for quite a long time. [#86419](https://github.com/ClickHouse/ClickHouse/pull/86419) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Make the staleness window in `timeSeries*()` functions left-open and right-closed. [#86588](https://github.com/ClickHouse/ClickHouse/pull/86588) ([Vitaly Baranov](https://github.com/vitlibar)).
* Add `FailedInternal*Query` profile events. [#86627](https://github.com/ClickHouse/ClickHouse/pull/86627) ([Shane Andrade](https://github.com/mauidude)).
* Fixes handling of users with a dot in the name when added via config file. [#86633](https://github.com/ClickHouse/ClickHouse/pull/86633) ([Mikhail Koviazin](https://github.com/mkmkme)).
* Add asynchronous metric for memory usage in queries (`QueriesMemoryUsage` and `QueriesPeakMemoryUsage`). [#86669](https://github.com/ClickHouse/ClickHouse/pull/86669) ([Azat Khuzhin](https://github.com/azat)).
* You can use `clickhouse-benchmark --precise` flag for more precise reporting of QPS and other per-interval metrics. It helps to get consistent QPS in case if durations of queries are comparable to the reporting interval `--delay D`. [#86684](https://github.com/ClickHouse/ClickHouse/pull/86684) ([Sergei Trifonov](https://github.com/serxa)).
* Make nice values of Linux threads configurable to assign some threads (merge/mutate, query, materialized view, zookeeper client) higher or lower priorities. [#86703](https://github.com/ClickHouse/ClickHouse/pull/86703) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Fix misleading “specified upload does not exist” error, which occurs when the original exception is lost in multipart upload because of a race condition. [#86725](https://github.com/ClickHouse/ClickHouse/pull/86725) ([Julia Kartseva](https://github.com/jkartseva)).
* Limit query plan description in the `EXPLAIN` query. Do not calculate the description for queries other than `EXPLAIN`. Added a setting `query_plan_max_step_description_length`. [#86741](https://github.com/ClickHouse/ClickHouse/pull/86741) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Add ability to tune pending signals in attempt to overcome CANNOT\_CREATE\_TIMER (for query profilers, `query_profiler_real_time_period_ns`/`query_profiler_cpu_time_period_ns`). And also collect `SigQ` from the `/proc/self/status` for introspection (if `ProcessSignalQueueSize` is near to `ProcessSignalQueueLimit`, then you will likely get `CANNOT_CREATE_TIMER` errors). [#86760](https://github.com/ClickHouse/ClickHouse/pull/86760) ([Azat Khuzhin](https://github.com/azat)).
* Improve performance of `RemoveRecursive` request in Keeper. [#86789](https://github.com/ClickHouse/ClickHouse/pull/86789) ([Antonio Andelic](https://github.com/antonio2368)).
* Remove extra whitespace in `PrettyJSONEachRow` during JSON type output. [#86819](https://github.com/ClickHouse/ClickHouse/pull/86819) ([Pavel Kruglov](https://github.com/Avogar)).
* Now we write blobs sizes of for `prefix.path` when directory is removed for plain rewriteable disk. [#86908](https://github.com/ClickHouse/ClickHouse/pull/86908) ([alesapin](https://github.com/alesapin)).
* Support performance tests against remote ClickHouse instances, including ClickHouse Cloud. Usage example: `tests/performance/scripts/perf.py tests/performance/math.xml --runs 10 --user --password --host --port --secure`. [#86995](https://github.com/ClickHouse/ClickHouse/pull/86995) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Respect memory limits in some places that are known to allocate significant (>16MiB) amount of memory (sorting, async inserts, file log). [#87035](https://github.com/ClickHouse/ClickHouse/pull/87035) ([Azat Khuzhin](https://github.com/azat)).
* Throw an exception if setting `network_compression_method` is not a supported generic codec. [#87097](https://github.com/ClickHouse/ClickHouse/pull/87097) ([Robert Schulze](https://github.com/rschu1ze)).
* System table `system.query_cache` now returns *all* query result cache entries, whereas it previously returned only shared entries or non-shared entries of the same user and role. That is okay as non-shared entries are supposed to not reveal *query results*, whereas `system.query_cache` returns *query strings*. This makes the behavior of the system table more similar to `system.query_log`. [#87104](https://github.com/ClickHouse/ClickHouse/pull/87104) ([Robert Schulze](https://github.com/rschu1ze)).
* Enable short circuit evaluation for `parseDateTime` function. [#87184](https://github.com/ClickHouse/ClickHouse/pull/87184) ([Pavel Kruglov](https://github.com/Avogar)).
* Add a new column `statistics` in `system.parts_columns`. [#87259](https://github.com/ClickHouse/ClickHouse/pull/87259) ([Han Fei](https://github.com/hanfei1991)).
#### Bug Fix (user-visible misbehavior in an official stable release)
* The results of alter queries are only validated on the initiator node for replicated databases and internally replicated tables. This will fix situations where an already committed alter query could get stuck on other nodes. [#83849](https://github.com/ClickHouse/ClickHouse/pull/83849) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Limit the number of tasks of each type in `BackgroundSchedulePool`. Avoid situations when all slots are occupied by task of one type, while other tasks are starving. Also avoids deadlocks when tasks wait for each other. This is controlled by `background_schedule_pool_max_parallel_tasks_per_type_ratio` server setting. [#84008](https://github.com/ClickHouse/ClickHouse/pull/84008) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Shutdown tables properly when recovering database replica. Improper shutdown would lead to LOGICAL\_ERROR for some table engines during database replica recovery. [#84744](https://github.com/ClickHouse/ClickHouse/pull/84744) ([Antonio Andelic](https://github.com/antonio2368)).
* Check access rights during typo correction hints generation for the database name. [#85371](https://github.com/ClickHouse/ClickHouse/pull/85371) ([Dmitry Novik](https://github.com/novikd)).
* 1. LowCardinality for hive columns 2. Fill hive columns before virtual columns (required for [https://github.com/ClickHouse/ClickHouse/pull/81040](https://github.com/ClickHouse/ClickHouse/pull/81040)) 3. LOGICAL\_ERROR on empty format for hive [#85528](https://github.com/ClickHouse/ClickHouse/issues/85528) 4. Fix check for hive partition columns being the only columns 5. Assert all hive columns are specified in the schema 6. Partial fix for parallel\_replicas\_cluster with hive 7. Use ordered container in extractkeyValuePairs for hive utils (required for [https://github.com/ClickHouse/ClickHouse/pull/81040](https://github.com/ClickHouse/ClickHouse/pull/81040)). [#85538](https://github.com/ClickHouse/ClickHouse/pull/85538) ([Arthur Passos](https://github.com/arthurpassos)).
* Prevent unnecessary optimization of the first argument of `IN` functions sometimes resulting in error when array mapping is used. [#85546](https://github.com/ClickHouse/ClickHouse/pull/85546) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Mapping between iceberg source ids and parquet names was not adjusted to the schema when the parquet file was written. This PR processes schema relevant for each iceberg data file, not a current one. [#85829](https://github.com/ClickHouse/ClickHouse/pull/85829) ([Daniil Ivanik](https://github.com/divanik)).
* Fix reading file size separately from opening it. Relates to [https://github.com/ClickHouse/ClickHouse/pull/33372](https://github.com/ClickHouse/ClickHouse/pull/33372), which was introduced in response to a bug in Linux kernels prior to `5.10` release. [#85837](https://github.com/ClickHouse/ClickHouse/pull/85837) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* ClickHouse Keeper no longer fails to start on systems where IPv6 is disabled at the kernel level (e.g., RHEL with ipv6.disable=1). It now attempts to fall back to an IPv4 listener if the initial IPv6 listener fails. [#85901](https://github.com/ClickHouse/ClickHouse/pull/85901) ([jskong1124](https://github.com/jskong1124)).
* This PR closes [#77990](https://github.com/ClickHouse/ClickHouse/issues/77990). Add TableFunctionRemote support for parallel replicas in globalJoin. [#85929](https://github.com/ClickHouse/ClickHouse/pull/85929) ([zoomxi](https://github.com/zoomxi)).
* Fix null pointer in orcschemareader::initializeifneeded(). this pr addresses the following issue: [#85292](https://github.com/ClickHouse/ClickHouse/issues/85292) ### documentation entry for user-facing changes. [#85951](https://github.com/ClickHouse/ClickHouse/pull/85951) ([yanglongwei](https://github.com/ylw510)).
* Add a check to allow correlated subqueries in the FROM clause only if they use columns from the outer query. Fixes [#85469](https://github.com/ClickHouse/ClickHouse/issues/85469). Fixes [#85402](https://github.com/ClickHouse/ClickHouse/issues/85402). [#85966](https://github.com/ClickHouse/ClickHouse/pull/85966) ([Dmitry Novik](https://github.com/novikd)).
* Fix alter update of a column with a subcolumn used in other column materialized expression. Previously materialized column with subcolumn in its expression was not updated properly. [#85985](https://github.com/ClickHouse/ClickHouse/pull/85985) ([Pavel Kruglov](https://github.com/Avogar)).
* Forbid altering columns whose subcolumns are used in PK or partition expression. [#86005](https://github.com/ClickHouse/ClickHouse/pull/86005) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix reading subcolumns with non-default column mapping mode in storage DeltaLake. [#86064](https://github.com/ClickHouse/ClickHouse/pull/86064) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix using wrong default values for path with Enum hint inside JSON. [#86065](https://github.com/ClickHouse/ClickHouse/pull/86065) ([Pavel Kruglov](https://github.com/Avogar)).
* DataLake hive catalog url parsing with input sanitisation. Closes [#86018](https://github.com/ClickHouse/ClickHouse/issues/86018). [#86092](https://github.com/ClickHouse/ClickHouse/pull/86092) ([rajat mohan](https://github.com/rajatmohan22)).
* Fix logical error during filesystem cache dynamic resize. Closes [#86122](https://github.com/ClickHouse/ClickHouse/issues/86122). Closes [https://github.com/ClickHouse/clickhouse-core-incidents/issues/473](https://github.com/ClickHouse/clickhouse-core-incidents/issues/473). [#86130](https://github.com/ClickHouse/ClickHouse/pull/86130) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Use `NonZeroUInt64` for `logs_to_keep` in DatabaseReplicatedSettings. [#86142](https://github.com/ClickHouse/ClickHouse/pull/86142) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Exception was thrown by a `FINAL` query with skip index if the table (e.g `ReplacingMergeTree`) was created with setting`index_granularity_bytes = 0`. That exception has been fixed now. [#86147](https://github.com/ClickHouse/ClickHouse/pull/86147) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Removes UB and fixes problems with parsing of Iceberg partition expression. [#86166](https://github.com/ClickHouse/ClickHouse/pull/86166) ([Daniil Ivanik](https://github.com/divanik)).
* Fix crash in case of const and non-const blocks in one INSERT. [#86230](https://github.com/ClickHouse/ClickHouse/pull/86230) ([Azat Khuzhin](https://github.com/azat)).
* Process includes from `/etc/metrika.xml` as a default when creating disks from SQL. [#86232](https://github.com/ClickHouse/ClickHouse/pull/86232) ([alekar](https://github.com/alekar)).
* Fix accurateCastOrNull/accurateCastOrDefault from String to JSON. [#86240](https://github.com/ClickHouse/ClickHouse/pull/86240) ([Pavel Kruglov](https://github.com/Avogar)).
* Support directories without '/' in iceberg engine. [#86249](https://github.com/ClickHouse/ClickHouse/pull/86249) ([scanhex12](https://github.com/scanhex12)).
* Fix crash with replaceRegex, a FixedString haystack and an empty needle. [#86270](https://github.com/ClickHouse/ClickHouse/pull/86270) ([Raúl Marín](https://github.com/Algunenano)).
* Fix crash during ALTER UPDATE Nullable(JSON). [#86281](https://github.com/ClickHouse/ClickHouse/pull/86281) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix missing column definer in system.tables. [#86295](https://github.com/ClickHouse/ClickHouse/pull/86295) ([Raúl Marín](https://github.com/Algunenano)).
* Fix cast from LowCardinality(Nullable(T)) to Dynamic. [#86365](https://github.com/ClickHouse/ClickHouse/pull/86365) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix logical error during writes to DeltaLake. Closes [#86175](https://github.com/ClickHouse/ClickHouse/issues/86175). [#86367](https://github.com/ClickHouse/ClickHouse/pull/86367) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix `416 The range specified is invalid for the current size of the resource. The range specified is invalid for the current size of the resource` when reading empty blobs from Azure blob storage for plain\_rewritable disk. [#86400](https://github.com/ClickHouse/ClickHouse/pull/86400) ([Julia Kartseva](https://github.com/jkartseva)).
* Fix GROUP BY Nullable(JSON). [#86410](https://github.com/ClickHouse/ClickHouse/pull/86410) ([Pavel Kruglov](https://github.com/Avogar)).
* Fixed a bug in Materialized Views: an MV might not work if it was created, dropped, and then created again with the same name. [#86413](https://github.com/ClickHouse/ClickHouse/pull/86413) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Fail if all replicas are unavailable when reading from \*cluster functions. [#86414](https://github.com/ClickHouse/ClickHouse/pull/86414) ([Julian Maicher](https://github.com/jmaicher)).
* Fix leaking of `MergesMutationsMemoryTracking` due to `Buffer` tables and fix `query_views_log` for streaming from `Kafka` (and others). [#86422](https://github.com/ClickHouse/ClickHouse/pull/86422) ([Azat Khuzhin](https://github.com/azat)).
* Fix show tables after dropping reference table of alias storage. [#86433](https://github.com/ClickHouse/ClickHouse/pull/86433) ([RinChanNOW](https://github.com/RinChanNOWWW)).
* Fix missing chunk header when send\_chunk\_header is enabled and UDF is invoked via HTTP protocol. [#86469](https://github.com/ClickHouse/ClickHouse/pull/86469) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix possible deadlock in case of jemalloc profile flushes enabled. [#86473](https://github.com/ClickHouse/ClickHouse/pull/86473) ([Azat Khuzhin](https://github.com/azat)).
* Fix reading subcolumns in DeltaLake table engine. Closes [#86204](https://github.com/ClickHouse/ClickHouse/issues/86204). [#86477](https://github.com/ClickHouse/ClickHouse/pull/86477) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Handling loopback host ID properly to avoid collision when processing DDL tasks:. [#86479](https://github.com/ClickHouse/ClickHouse/pull/86479) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Fix detach/attach for postgres database engine tables with numeric/decimal columns. [#86480](https://github.com/ClickHouse/ClickHouse/pull/86480) ([Julian Maicher](https://github.com/jmaicher)).
* Fix use of uninitialized memory in getSubcolumnType. [#86498](https://github.com/ClickHouse/ClickHouse/pull/86498) ([Raúl Marín](https://github.com/Algunenano)).
* Functions `searchAny` and `searchAll` when called with empty needles now return `true` (aka. "matches everything"). Previously, they returned `false`. (issue [#86300](https://github.com/ClickHouse/ClickHouse/issues/86300)). [#86500](https://github.com/ClickHouse/ClickHouse/pull/86500) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Fix function `timeSeriesResampleToGridWithStaleness()` when the first bucket has no value. [#86507](https://github.com/ClickHouse/ClickHouse/pull/86507) ([Vitaly Baranov](https://github.com/vitlibar)).
* Fix crash caused by `merge_tree_min_read_task_size` being set to 0. [#86527](https://github.com/ClickHouse/ClickHouse/pull/86527) ([yanglongwei](https://github.com/ylw510)).
* While reading takes format for each data file from Iceberg metadata (earlier it was taken from table arguments). [#86529](https://github.com/ClickHouse/ClickHouse/pull/86529) ([Daniil Ivanik](https://github.com/divanik)).
* Ignore exceptions during flushing log on shutdown and make shutdown more safe (to avoid SIGSEGV). [#86546](https://github.com/ClickHouse/ClickHouse/pull/86546) ([Azat Khuzhin](https://github.com/azat)).
* Fix Backup db engine raising exception on query with zero sized part files. [#86563](https://github.com/ClickHouse/ClickHouse/pull/86563) ([Max Justus Spransy](https://github.com/maxjustus)).
* Fix missing chunk header when send\_chunk\_header is enabled and UDF is invoked via HTTP protocol. [#86606](https://github.com/ClickHouse/ClickHouse/pull/86606) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix S3Queue logical error "Expected current processor {} to be equal to {}", which happened because of keeper session expiration. [#86615](https://github.com/ClickHouse/ClickHouse/pull/86615) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Nullablity bugs in insert and pruning. This closes [#86407](https://github.com/ClickHouse/ClickHouse/issues/86407). [#86630](https://github.com/ClickHouse/ClickHouse/pull/86630) ([scanhex12](https://github.com/scanhex12)).
* Do not disable file system cache if Iceberg metadata cache is disabled. [#86635](https://github.com/ClickHouse/ClickHouse/pull/86635) ([Daniil Ivanik](https://github.com/divanik)).
* Fixed 'Deadlock in Parquet::ReadManager (single-threaded)' error in parquet reader v3. [#86644](https://github.com/ClickHouse/ClickHouse/pull/86644) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix support for IPv6 in `listen_host` for ArrowFlight. [#86664](https://github.com/ClickHouse/ClickHouse/pull/86664) ([Vitaly Baranov](https://github.com/vitlibar)).
* Fix shutdown in `ArrowFlight` handler. This PR fixes [#86596](https://github.com/ClickHouse/ClickHouse/issues/86596). [#86665](https://github.com/ClickHouse/ClickHouse/pull/86665) ([Vitaly Baranov](https://github.com/vitlibar)).
* Fix distributed queries with `describe_compact_output=1`. [#86676](https://github.com/ClickHouse/ClickHouse/pull/86676) ([Azat Khuzhin](https://github.com/azat)).
* Fix window definition parsing and applying query parameters. [#86720](https://github.com/ClickHouse/ClickHouse/pull/86720) ([Azat Khuzhin](https://github.com/azat)).
* Fix exception `Partition strategy wildcard can not be used without a '_partition_id' wildcard.` when creating a table with `PARTITION BY`, but without partition wildcard, which used to work in versions before 25.8. Closes [https://github.com/ClickHouse/clickhouse-private/issues/37567](https://github.com/ClickHouse/clickhouse-private/issues/37567). [#86748](https://github.com/ClickHouse/ClickHouse/pull/86748) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix LogicalError if parallel queries are trying to acquire single lock. [#86751](https://github.com/ClickHouse/ClickHouse/pull/86751) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Fix writing NULL into JSON shared data in RowBinary input format and add some additional validations in ColumnObject. [#86812](https://github.com/ClickHouse/ClickHouse/pull/86812) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix empty Tuple permutation with limit. [#86828](https://github.com/ClickHouse/ClickHouse/pull/86828) ([Pavel Kruglov](https://github.com/Avogar)).
* Do not use separate keeper node for persistent processing nodes. Fix for [https://github.com/ClickHouse/ClickHouse/pull/85995](https://github.com/ClickHouse/ClickHouse/pull/85995). Closes [#86406](https://github.com/ClickHouse/ClickHouse/issues/86406). [#86841](https://github.com/ClickHouse/ClickHouse/pull/86841) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix TimeSeries engine table breaking creation of new replica in Replicated Database. [#86845](https://github.com/ClickHouse/ClickHouse/pull/86845) ([Nikolay Degterinsky](https://github.com/evillique)).
* Fix querying `system.distributed_ddl_queue` in cases where tasks are missing certain Keeper nodes. [#86848](https://github.com/ClickHouse/ClickHouse/pull/86848) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix seeking at the end of the decompressed block. [#86906](https://github.com/ClickHouse/ClickHouse/pull/86906) ([Pavel Kruglov](https://github.com/Avogar)).
* Process exception which is thrown during asyncronous execution of Iceberg Iterator. [#86932](https://github.com/ClickHouse/ClickHouse/pull/86932) ([Daniil Ivanik](https://github.com/divanik)).
* Fix saving of big preprocessed XML configs. [#86934](https://github.com/ClickHouse/ClickHouse/pull/86934) ([c-end](https://github.com/c-end)).
* Fix date field populating in system.iceberg\_metadata\_log table. [#86961](https://github.com/ClickHouse/ClickHouse/pull/86961) ([Daniil Ivanik](https://github.com/divanik)).
* Fixed infinite recalculation of `TTL` with `WHERE`. [#86965](https://github.com/ClickHouse/ClickHouse/pull/86965) ([Anton Popov](https://github.com/CurtizJ)).
* Fixed possible incorrect result of `uniqExact` function with `ROLLUP` and `CUBE` modifiers. [#87014](https://github.com/ClickHouse/ClickHouse/pull/87014) ([Nikita Taranov](https://github.com/nickitat)).
* Fix resolving table schema with `url()` table function when `parallel_replicas_for_cluster_functions` setting is set to 1. [#87029](https://github.com/ClickHouse/ClickHouse/pull/87029) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Correctly cast output of PREWHERE after splitting it into multiple steps. [#87040](https://github.com/ClickHouse/ClickHouse/pull/87040) ([Antonio Andelic](https://github.com/antonio2368)).
* Fixed lightweight updates with `ON CLUSTER` clause. [#87043](https://github.com/ClickHouse/ClickHouse/pull/87043) ([Anton Popov](https://github.com/CurtizJ)).
* Fix compatibility of some aggregate function states with String argument. [#87049](https://github.com/ClickHouse/ClickHouse/pull/87049) ([Pavel Kruglov](https://github.com/Avogar)).
* Fixes an issue where model name from OpenAI wasn't passed through. [#87100](https://github.com/ClickHouse/ClickHouse/pull/87100) ([Kaushik Iska](https://github.com/iskakaushik)).
* EmbeddedRocksDB: Path must be inside user\_files. [#87109](https://github.com/ClickHouse/ClickHouse/pull/87109) ([Raúl Marín](https://github.com/Algunenano)).
* Fix KeeperMap tables created before 25.1, leaving data in ZooKeeper after the DROP query. [#87112](https://github.com/ClickHouse/ClickHouse/pull/87112) ([Nikolay Degterinsky](https://github.com/evillique)).
* Fix maps and arrays field ids reading parquet. [#87136](https://github.com/ClickHouse/ClickHouse/pull/87136) ([scanhex12](https://github.com/scanhex12)).
* Fix reading array with array sizes subcolumn in lazy materialization. [#87139](https://github.com/ClickHouse/ClickHouse/pull/87139) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix CASE function with Dynamic arguments. [#87177](https://github.com/ClickHouse/ClickHouse/pull/87177) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix reading empty array from empty string in CSV. [#87182](https://github.com/ClickHouse/ClickHouse/pull/87182) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix possible wrong result of non-correlated `EXISTS`. It was broken with `execute_exists_as_scalar_subquery=1` which was introduced in [https://github.com/ClickHouse/ClickHouse/pull/85481](https://github.com/ClickHouse/ClickHouse/pull/85481) and affects `25.8`. Fixes [#86415](https://github.com/ClickHouse/ClickHouse/issues/86415). [#87207](https://github.com/ClickHouse/ClickHouse/pull/87207) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Throws an error if iceberg\_metadata\_log is not configured, but user tries to get debug iceberg metadata info. Fixes nullptr access. [#87250](https://github.com/ClickHouse/ClickHouse/pull/87250) ([Daniil Ivanik](https://github.com/divanik)).
#### Build/Testing/Packaging Improvement
* Fix compatibility with abseil-cpp 20250814.0, [https://github.com/abseil/abseil-cpp/issues/1923](https://github.com/abseil/abseil-cpp/issues/1923). [#85970](https://github.com/ClickHouse/ClickHouse/pull/85970) ([Yuriy Chernyshov](https://github.com/georgthegreat)).
* Put building standalone WASM lexer under a flag. [#86505](https://github.com/ClickHouse/ClickHouse/pull/86505) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fix crc32c build on older ARM CPUs without support for the `vmull_p64` instruction. [#86521](https://github.com/ClickHouse/ClickHouse/pull/86521) ([Pablo Marcos](https://github.com/pamarcos)).
* Use `openldap` 2.6.10. [#86623](https://github.com/ClickHouse/ClickHouse/pull/86623) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Do not try to intercept `memalign` on darwin. [#86769](https://github.com/ClickHouse/ClickHouse/pull/86769) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Use `krb5` 1.22.1-final. [#86836](https://github.com/ClickHouse/ClickHouse/pull/86836) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fix unpacking Rust crate names in `list-licenses.sh`. [#87305](https://github.com/ClickHouse/ClickHouse/pull/87305) ([Konstantin Bogdanov](https://github.com/thevar1able)).
ClickHouse release 25.8 LTS, 2025-08-28
#### Backward Incompatible Change
* Infer `Array(Dynamic)` instead of unnamed `Tuple` for arrays of values with different types in JSON. To use the previous behaviour, disable setting `input_format_json_infer_array_of_dynamic_from_array_of_different_types`. [#80859](https://github.com/ClickHouse/ClickHouse/pull/80859) ([Pavel Kruglov](https://github.com/Avogar)).
* Move S3 latency metrics to histograms for homogeneity and simplicity. [#82305](https://github.com/ClickHouse/ClickHouse/pull/82305) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Require backticks around identifiers with dots in default expressions to prevent them from being parsed as compound identifiers. [#83162](https://github.com/ClickHouse/ClickHouse/pull/83162) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Lazy materialization is enabled only with analyzer (which is the default) to avoid maintenance without analyzer, — which, in our experience, have some issues (for example, when using `indexHint()` in conditions). [#83791](https://github.com/ClickHouse/ClickHouse/pull/83791) ([Igor Nikonov](https://github.com/devcrafter)).
* Write values of `Enum` type as `BYTE_ARRAY` with `ENUM` logical type in Parquet output format by default. [#84169](https://github.com/ClickHouse/ClickHouse/pull/84169) ([Pavel Kruglov](https://github.com/Avogar)).
* Enable MergeTree setting `write_marks_for_substreams_in_compact_parts` by default. It significantly improves performance of subcolumns reading from newly created Compact parts. Servers with version less then 25.5 won't be able to read new Compact parts. [#84171](https://github.com/ClickHouse/ClickHouse/pull/84171) ([Pavel Kruglov](https://github.com/Avogar)).
* The previous `concurrent_threads_scheduler` default value was `round_robin`, which proved unfair in the presence of a high number of single-threaded queries (e.g., INSERTs). This change makes a safer alternative `fair_round_robin` scheduler, the default. [#84747](https://github.com/ClickHouse/ClickHouse/pull/84747) ([Sergei Trifonov](https://github.com/serxa)).
* ClickHouse supports PostgreSQL-style heredoc syntax: `$tag$ string contents... $tag$`, also known as dollar-quoted string literals. In previous versions, there were fewer restrictions on tags: they could contain arbitrary characters, including punctuation and whitespace. This introduces parsing ambiguity with identifiers that can also start with a dollar character. At the same time, PostgreSQL only allows word characters for tags. To resolve the problem, we now restrict heredoc tags only to contain word characters. Closes [#84731](https://github.com/ClickHouse/ClickHouse/issues/84731). [#84846](https://github.com/ClickHouse/ClickHouse/pull/84846) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* The functions `azureBlobStorage`, `deltaLakeAzure`, and `icebergAzure` have been updated to properly validate `AZURE` permissions. All cluster-variant functions (`-Cluster` functions) now verify permissions against their corresponding non-clustered counterparts. Additionally, the `icebergLocal` and `deltaLakeLocal` functions now enforce `FILE` permission checks. [#84938](https://github.com/ClickHouse/ClickHouse/pull/84938) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Enables `allow_dynamic_metadata_for_data_lakes` setting (Table Engine level setting) by default. [#85044](https://github.com/ClickHouse/ClickHouse/pull/85044) ([Daniil Ivanik](https://github.com/divanik)).
* Disable quoting 64 bit integers in JSON formats by default. [#74079](https://github.com/ClickHouse/ClickHouse/pull/74079) ([Pavel Kruglov](https://github.com/Avogar))
#### New Feature
* Basic support for the PromQL dialect is added. To use it, set `dialect='promql'` in clickhouse-client, point it to the TimeSeries table using the setting `promql_table_name='X'` and execute queries like `rate(ClickHouseProfileEvents_ReadCompressedBytes[1m])[5m:1m]`. In addition you can wrap the PromQL query with SQL: `SELECT * FROM prometheusQuery('up', ...);`. So far only functions `rate`, `delta` and `increase` are supported. No unary/binary operators. No HTTP API. [#75036](https://github.com/ClickHouse/ClickHouse/pull/75036) ([Vitaly Baranov](https://github.com/vitlibar)).
* AI Powered SQL generation can now infer from env ANTHROPIC\_API\_KEY and OPENAI\_API\_KEY if available, this is to make it so that we can have a zero config option to use this feature. [#83787](https://github.com/ClickHouse/ClickHouse/pull/83787) ([Kaushik Iska](https://github.com/iskakaushik)).
* Implement support for [ArrowFlight RPC](https://arrow.apache.org/docs/format/Flight.html) protocol by adding: - new table function `arrowflight`. [#74184](https://github.com/ClickHouse/ClickHouse/pull/74184) ([zakr600](https://github.com/zakr600)).
* Now all tables support the `_table` virtual column (not only tables with the `Merge` engine), which is especially useful for queries with UNION ALL. [#63665](https://github.com/ClickHouse/ClickHouse/pull/63665) ([Xiaozhe Yu](https://github.com/wudidapaopao)).
* Allow to use any storage policy (i.e. object storage, such as S3) for external aggregation/sorting. [#84734](https://github.com/ClickHouse/ClickHouse/pull/84734) ([Azat Khuzhin](https://github.com/azat)).
* Implement AWS S3 authentication with an explicitly provided IAM role. Implement OAuth for GCS. These features were recently only available in ClickHouse Cloud and are now open-sourced. Synchronize some interfaces such as serialization of the connection parameters for object storages. [#84011](https://github.com/ClickHouse/ClickHouse/pull/84011) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Support position deletes for Iceberg TableEngine. [#83094](https://github.com/ClickHouse/ClickHouse/pull/83094) ([Daniil Ivanik](https://github.com/divanik)).
* Support Iceberg Equality Deletes. [#85843](https://github.com/ClickHouse/ClickHouse/pull/85843) ([Han Fei](https://github.com/hanfei1991)).
* Iceberg writes for create. Closes [#83927](https://github.com/ClickHouse/ClickHouse/issues/83927). [#83983](https://github.com/ClickHouse/ClickHouse/pull/83983) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Glue catalogs for writes. [#84136](https://github.com/ClickHouse/ClickHouse/pull/84136) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Iceberg Rest catalogs for writes. [#84684](https://github.com/ClickHouse/ClickHouse/pull/84684) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Merge all iceberg position delete files into data files. This will reduce amount and sizes of parquet files in iceberg storage. Syntax: `OPTIMIZE TABLE table_name`. [#85250](https://github.com/ClickHouse/ClickHouse/pull/85250) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Support `drop table` for iceberg (Removing from REST/Glue catalogs + removing metadata about table). [#85395](https://github.com/ClickHouse/ClickHouse/pull/85395) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Support alter delete mutations for iceberg in merge-on-read format. [#85549](https://github.com/ClickHouse/ClickHouse/pull/85549) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Support writes into DeltaLake. Closes [#79603](https://github.com/ClickHouse/ClickHouse/issues/79603). [#85564](https://github.com/ClickHouse/ClickHouse/pull/85564) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Added setting `delta_lake_snapshot_version` to allow reading specific snapshot version in table engine `DeltaLake`. [#85295](https://github.com/ClickHouse/ClickHouse/pull/85295) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Write more iceberg statistics (column sizes, lower and upper bounds) in metadata (manifest entries) for min-max pruning. [#85746](https://github.com/ClickHouse/ClickHouse/pull/85746) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Support add/drop/modify columns in iceberg for simple types. [#85769](https://github.com/ClickHouse/ClickHouse/pull/85769) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Iceberg: support writing version-hint file. This closes [#85097](https://github.com/ClickHouse/ClickHouse/issues/85097). [#85130](https://github.com/ClickHouse/ClickHouse/pull/85130) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Views, created by ephemeral users, will now store a copy of an actual user and will no longer be invalidated after the ephemeral user is deleted. [#84763](https://github.com/ClickHouse/ClickHouse/pull/84763) ([pufit](https://github.com/pufit)).
* The vector similarity index now supports binary quantization. Binary quantization significantly reduces the memory consumption and speeds up the process of building a vector index (due to faster distance calculation). Also, the existing setting `vector_search_postfilter_multiplier `was made obsolete and replaced by a more general setting : `vector_search_index_fetch_multiplier`. [#85024](https://github.com/ClickHouse/ClickHouse/pull/85024) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Allow key value arguments in `s3` or `s3Cluster` table engine/function, e.g. for example `s3('url', CSV, structure = 'a Int32', compression_method = 'gzip')`. [#85134](https://github.com/ClickHouse/ClickHouse/pull/85134) ([Kseniia Sumarokova](https://github.com/kssenii)).
* A new system table to keep erroneous incoming messages from engines like kafka ("dead letter queue"). [#68873](https://github.com/ClickHouse/ClickHouse/pull/68873) ([Ilya Golshtein](https://github.com/ilejn)).
* The new SYSTEM RESTORE DATABASE REPLICA for Replicated databases, similar to the existing functionality for restore in ReplicatedMergeTree. [#73100](https://github.com/ClickHouse/ClickHouse/pull/73100) ([Konstantin Morozov](https://github.com/k-morozov)).
* PostgreSQL protocol now supports the `COPY` command. [#74344](https://github.com/ClickHouse/ClickHouse/pull/74344) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Support C# client for mysql protocol. This closes [#83992](https://github.com/ClickHouse/ClickHouse/issues/83992). [#84397](https://github.com/ClickHouse/ClickHouse/pull/84397) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Add support for hive partition style reads and writes. [#76802](https://github.com/ClickHouse/ClickHouse/pull/76802) ([Arthur Passos](https://github.com/arthurpassos)).
* Add `zookeeper_connection_log` system table to store historical information about ZooKeeper connections. [#79494](https://github.com/ClickHouse/ClickHouse/pull/79494) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Server setting `cpu_slot_preemption` enables preemptive CPU scheduling for workloads and ensures max-min fair allocation of CPU time among workloads. New workload settings for CPU throttling are added: `max_cpus`, `max_cpu_share` and `max_burst_cpu_seconds`. More details: [https://clickhouse.com/docs/operations/workload-scheduling#cpu\_scheduling](https://clickhouse.com/docs/operations/workload-scheduling#cpu_scheduling). [#80879](https://github.com/ClickHouse/ClickHouse/pull/80879) ([Sergei Trifonov](https://github.com/serxa)).
* Drop TCP connection after a configured number of queries or time threshold. This makes sense for a more uniform connection distribution between cluster nodes behind a load balancer. Resolves [#68000](https://github.com/ClickHouse/ClickHouse/issues/68000). [#81472](https://github.com/ClickHouse/ClickHouse/pull/81472) ([Kenny Sun](https://github.com/hwabis)).
* Parallel replicas now support using projections for queries. [#82659](https://github.com/ClickHouse/ClickHouse/issues/82659). [#82807](https://github.com/ClickHouse/ClickHouse/pull/82807) ([zoomxi](https://github.com/zoomxi)).
* Support DESCRIBE SELECT in addition to DESCRIBE (SELECT ...). [#82947](https://github.com/ClickHouse/ClickHouse/pull/82947) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Force secure connection for mysql\_port and postgresql\_port. [#82962](https://github.com/ClickHouse/ClickHouse/pull/82962) ([tiandiwonder](https://github.com/tiandiwonder)).
* You can now do case-insensitive JSON key lookups using `JSONExtractCaseInsensitive` (and other variants of `JSONExtract`). [#83770](https://github.com/ClickHouse/ClickHouse/pull/83770) ([Alistair Evans](https://github.com/alistairjevans)).
* Introduction of `system.completions` table. Closes [#81889](https://github.com/ClickHouse/ClickHouse/issues/81889). [#83833](https://github.com/ClickHouse/ClickHouse/pull/83833) ([|2ustam](https://github.com/RuS2m)).
* Added a new function `nowInBlock64`. Example usage: `SELECT nowInBlock64(6)` returns `2025-07-29 17:09:37.775725`. [#84178](https://github.com/ClickHouse/ClickHouse/pull/84178) ([Halersson Paris](https://github.com/halersson)).
* Add extra\_credentials to AzureBlobStorage to authenticate with client\_id and tenant\_id. [#84235](https://github.com/ClickHouse/ClickHouse/pull/84235) ([Pablo Marcos](https://github.com/pamarcos)).
* Added function `dateTimeToUUIDv7` to convert a DateTime value to a UUIDv7. Example usage: `SELECT dateTimeToUUIDv7(toDateTime('2025-08-15 18:57:56'))` returns `0198af18-8320-7a7d-abd3-358db23b9d5c`. [#84319](https://github.com/ClickHouse/ClickHouse/pull/84319) ([samradovich](https://github.com/samradovich)).
* `timeSeriesDerivToGrid` and `timeSeriesPredictLinearToGrid` aggregate functions to re-sample data to a time grid defined by the specified start timestamp, end timestamp, and step; calculates PromQL-like `deriv` and `predict_linear`, respectively. [#84328](https://github.com/ClickHouse/ClickHouse/pull/84328) ([Stephen Chi](https://github.com/stephchi0)).
* Add two new TimeSeries functions: - `timeSeriesRange(start_timestamp, end_timestamp, step)`, - `timeSeriesFromGrid(start_timestamp, end_timestamp, step, values)`,. [#85435](https://github.com/ClickHouse/ClickHouse/pull/85435) ([Vitaly Baranov](https://github.com/vitlibar)).
* New syntax added `GRANT READ ON S3('s3://foo/.*') TO user`. [#84503](https://github.com/ClickHouse/ClickHouse/pull/84503) ([pufit](https://github.com/pufit)).
* Added `Hash` as a new output format. It calculates a single hash value for all columns and rows of the result. This is useful for calculating a "fingerprint" of the result, for example, in use cases where data transfer is a bottleneck. Example: `SELECT arrayJoin(['abc', 'def']), 42 FORMAT Hash` returns `e5f9e676db098fdb9530d2059d8c23ef`. [#84607](https://github.com/ClickHouse/ClickHouse/pull/84607) ([Robert Schulze](https://github.com/rschu1ze)).
* Add the ability to set up arbitrary watches in Keeper Multi queries. [#84964](https://github.com/ClickHouse/ClickHouse/pull/84964) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Adds an option `--max-concurrency` for the `clickhouse-benchmark` tool that enables a mode with a gradual increase in the number of parallel queries. [#85623](https://github.com/ClickHouse/ClickHouse/pull/85623) ([Sergei Trifonov](https://github.com/serxa)).
* Support partially aggregated metrics. [#85328](https://github.com/ClickHouse/ClickHouse/pull/85328) ([Mikhail Artemenko](https://github.com/Michicosun)).
#### Experimental Feature
* Enable correlated subqueries support by default, they are no longer experimental. [#85107](https://github.com/ClickHouse/ClickHouse/pull/85107) ([Dmitry Novik](https://github.com/novikd)).
* Unity, Glue, Rest, and Hive Metastore data lake catalogs are promoted from experimental to beta. [#85848](https://github.com/ClickHouse/ClickHouse/pull/85848) ([Melvyn Peignon](https://github.com/melvynator)).
* Lightweight updates and deletes are promoted from experimental to beta.
* Approximate vector search with vector similarity indexes is now GA. [#85888](https://github.com/ClickHouse/ClickHouse/pull/85888) ([Robert Schulze](https://github.com/rschu1ze)).
* Ytsaurus table engine and table function. [#77606](https://github.com/ClickHouse/ClickHouse/pull/77606) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* Previously, the text index data would be separated into multiple segments (each segment size by default was 256 MiB). This might reduce the memory consumption while building the text index, however this increases the space requirement on the disk and increase the query response time. [#84590](https://github.com/ClickHouse/ClickHouse/pull/84590) ([Elmi Ahmadov](https://github.com/ahmadov)).
#### Performance Improvement
* New parquet reader implementation. It's generally faster and supports page-level filter pushdown and PREWHERE. Currently experimental. Use setting `input_format_parquet_use_native_reader_v3` to enable. [#82789](https://github.com/ClickHouse/ClickHouse/pull/82789) ([Michael Kolupaev](https://github.com/al13n321)).
* Replaced the official HTTP transport in Azure library with our own HTTP client implementation for Azure Blob Storage. Introduced multiple settings for this clients which mirror settings from S3. Introduced aggressive connection timeouts for both Azure and S3. Improved introspection into Azure profile events and metrics. New client is enabled by default, provide much better latencies for cold queries on top of Azure Blob Storage. Old `Curl` client can be returned back by setting `azure_sdk_use_native_client=false`. [#83294](https://github.com/ClickHouse/ClickHouse/pull/83294) ([alesapin](https://github.com/alesapin)). The previous, official implementation of Azure client was unsuitable for production due to terrible latency spikes, ranging from five seconds to minutes. We have ditched that terrible implementation and are very proud of that.
* Processes indexes in increasing order of file size. The net index ordering prioritizes minmax and vector indexes (due to simplicity and selectivity respectively), and small indexes thereafter. Within the minmax/vector indexes smaller indexes are also preferred. [#84094](https://github.com/ClickHouse/ClickHouse/pull/84094) ([Maruth Goyal](https://github.com/maruthgoyal)).
* Enable MergeTree setting `write_marks_for_substreams_in_compact_parts` by default. It significantly improves performance of subcolumns reading from newly created Compact parts. Servers with version less then 25.5 won't be able to read new Compact parts. [#84171](https://github.com/ClickHouse/ClickHouse/pull/84171) ([Pavel Kruglov](https://github.com/Avogar)).
* `azureBlobStorage` table engine: cache and reuse managed identity authentication tokens when possible to avoid throttling. [#79860](https://github.com/ClickHouse/ClickHouse/pull/79860) ([Nick Blakely](https://github.com/niblak)).
* `ALL` `LEFT/INNER` JOINs will be automatically converted to `RightAny` if the right side is functionally determined by the join key columns (all rows have unique join key values). [#84010](https://github.com/ClickHouse/ClickHouse/pull/84010) ([Nikita Taranov](https://github.com/nickitat)).
* Add `max_joined_block_size_bytes` in addition to `max_joined_block_size_rows` to limit the memory usage of JOINs with heavy columns. [#83869](https://github.com/ClickHouse/ClickHouse/pull/83869) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Added new logic (controlled by the setting `enable_producing_buckets_out_of_order_in_aggregation`, enabled by default) that allows sending some buckets out of order during memory-efficient aggregation. When some aggregation buckets take significantly longer to merge than others, it improves performance by allowing the initiator to merge buckets with higher bucket id-s in the meantime. The downside is potentially higher memory usage (shouldn't be significant). [#80179](https://github.com/ClickHouse/ClickHouse/pull/80179) ([Nikita Taranov](https://github.com/nickitat)).
* Introduced the `optimize_rewrite_regexp_functions` setting (enabled by default), which allows the optimizer to rewrite certain `replaceRegexpAll`, `replaceRegexpOne`, and `extract` calls into simpler and more efficient forms when specific regular expression patterns are detected. (issue [#81981](https://github.com/ClickHouse/ClickHouse/issues/81981)). [#81992](https://github.com/ClickHouse/ClickHouse/pull/81992) ([Amos Bird](https://github.com/amosbird)).
* Process `max_joined_block_rows` outside of hash JOIN main loop. Slightly better performance for ALL JOIN. [#83216](https://github.com/ClickHouse/ClickHouse/pull/83216) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Process higher granularity min-max indexes first. Closes [#75381](https://github.com/ClickHouse/ClickHouse/issues/75381). [#83798](https://github.com/ClickHouse/ClickHouse/pull/83798) ([Maruth Goyal](https://github.com/maruthgoyal)).
* Make `DISTINCT` window aggregates run in linear time and fix a bug in `sumDistinct`. Closes [#79792](https://github.com/ClickHouse/ClickHouse/issues/79792). Closes [#52253](https://github.com/ClickHouse/ClickHouse/issues/52253). [#79859](https://github.com/ClickHouse/ClickHouse/pull/79859) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Vector search queries using a vector similarity index complete with lower latency due to reduced storage reads and reduced CPU usage. [#83803](https://github.com/ClickHouse/ClickHouse/pull/83803) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Rendezvous hashing for improve cache locality of workload distribution among parallel replicas. [#82511](https://github.com/ClickHouse/ClickHouse/pull/82511) ([Anton Ivashkin](https://github.com/ianton-ru)).
* Implement addManyDefaults for If combinators, so now aggregate functions with If combinators work faster. [#83870](https://github.com/ClickHouse/ClickHouse/pull/83870) ([Raúl Marín](https://github.com/Algunenano)).
* Calculate serialized key columnarly when group by multiple string or number columns. [#83884](https://github.com/ClickHouse/ClickHouse/pull/83884) ([李扬](https://github.com/taiyang-li)).
* Eliminated full scans for the cases when index analysis results in empty ranges for parallel replicas reading. [#84971](https://github.com/ClickHouse/ClickHouse/pull/84971) ([Eduard Karacharov](https://github.com/korowa)).
* Try -falign-functions=64 in attempt for more stable perf tests. [#83920](https://github.com/ClickHouse/ClickHouse/pull/83920) ([Azat Khuzhin](https://github.com/azat)).
* The bloom filter index is now used for conditions like `has([c1, c2, ...], column)`, where `column` is not of an `Array` type. This improves performance for such queries, making them as efficient as the `IN` operator. [#83945](https://github.com/ClickHouse/ClickHouse/pull/83945) ([Doron David](https://github.com/dorki)).
* Reduce unnecessary memcpy calls in CompressedReadBufferBase::readCompressedData. [#83986](https://github.com/ClickHouse/ClickHouse/pull/83986) ([Raúl Marín](https://github.com/Algunenano)).
* Optimize `largestTriangleThreeBuckets` by removing temporary data. [#84479](https://github.com/ClickHouse/ClickHouse/pull/84479) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Optimize string deserialization by simplifying the code. Closes [#38564](https://github.com/ClickHouse/ClickHouse/issues/38564). [#84561](https://github.com/ClickHouse/ClickHouse/pull/84561) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fixed the calculation of the minimal task size for parallel replicas. [#84752](https://github.com/ClickHouse/ClickHouse/pull/84752) ([Nikita Taranov](https://github.com/nickitat)).
* Improved performance of applying patch parts in `Join` mode. [#85040](https://github.com/ClickHouse/ClickHouse/pull/85040) ([Anton Popov](https://github.com/CurtizJ)).
* Remove zero byte. Closes [#85062](https://github.com/ClickHouse/ClickHouse/issues/85062). A few minor bugs were fixed. Functions `structureToProtobufSchema`, `structureToCapnProtoSchema` didn't correctly put a zero-terminating byte and were using a newline instead of it. That was leading to a missing newline in the output, and could lead to buffer overflows while using other functions that depend on the zero byte (such as `logTrace`, `demangle`, `extractURLParameter`, `toStringCutToZero`, and `encrypt`/`decrypt`). The `regexp_tree` dictionary layout didn't support processing strings with zero bytes. The `formatRowNoNewline` function, called with `Values` format or with any other format without a newline at the end of rows, erroneously cuts the last character of the output. Function `stem` contained an exception-safety error that could lead to a memory leak in a very rare scenario. The `initcap` function worked in the wrong way for `FixedString` arguments: it didn't recognize the start of the word at the start of the string if the previous string in a block ended with a word character. Fixed a security vulnerability of the Apache `ORC` format, which could lead to the exposure of uninitialized memory. Changed behavior of the function `replaceRegexpAll` and the corresponding alias, `REGEXP_REPLACE`: now it can do an empty match at the end of the string even if the previous match processed the whole string, such as in the case of `^a*|a*$` or `^|.*` - this corresponds to the semantic of JavaScript, Perl, Python, PHP, Ruby, but differs to the semantic of PostgreSQL. Implementation of many functions has been simplified and optimized. Documentation for several functions was wrong and has now been fixed. Keep in mind that the output of `byteSize` for String columns and complex types, which consisted of String columns, has changed (from 9 bytes per empty string to 8 bytes per empty string), and this is normal. [#85063](https://github.com/ClickHouse/ClickHouse/pull/85063) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Optimize the materialization of constants in cases when we do this materialization only to return a single row. [#85071](https://github.com/ClickHouse/ClickHouse/pull/85071) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Improve parallel files processing with delta-kernel-rs backend. [#85642](https://github.com/ClickHouse/ClickHouse/pull/85642) ([Azat Khuzhin](https://github.com/azat)).
* A new setting, enable\_add\_distinct\_to\_in\_subqueries, has been introduced. When enabled, ClickHouse will automatically add DISTINCT to subqueries in IN clauses for distributed queries. This can significantly reduce the size of temporary tables transferred between shards and improve network efficiency. Note: This is a trade-off—while network transfer is reduced, additional merging (deduplication) work is required on each node. Enable this setting when network transfer is a bottleneck and the merging cost is acceptable. [#81908](https://github.com/ClickHouse/ClickHouse/pull/81908) ([fhw12345](https://github.com/fhw12345)).
* Reduce query memory tracking overhead for executable user-defined functions. [#83929](https://github.com/ClickHouse/ClickHouse/pull/83929) ([Eduard Karacharov](https://github.com/korowa)).
* Implement internal `delta-kernel-rs` filtering (statistics and partition pruning) in storage `DeltaLake`. [#84006](https://github.com/ClickHouse/ClickHouse/pull/84006) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Disable skipping indexes that depend on columns updated on the fly or by patch parts more granularly. Now, skipping indexes are not used only in parts affected by on-the-fly mutations or patch parts; previously, those indexes were disabled for all parts. [#84241](https://github.com/ClickHouse/ClickHouse/pull/84241) ([Anton Popov](https://github.com/CurtizJ)).
* Allocate the minimum amount of memory needed for encrypted\_buffer for encrypted named collections. [#84432](https://github.com/ClickHouse/ClickHouse/pull/84432) ([Pablo Marcos](https://github.com/pamarcos)).
* Improved support for bloom filter indexes (regular, ngram, and token) to be utilized when the first argument is a constant array (the set) and the second is the indexed column (the subset), enabling more efficient query execution. [#84700](https://github.com/ClickHouse/ClickHouse/pull/84700) ([Doron David](https://github.com/dorki)).
* Reduce contention on storage lock in Keeper. [#84732](https://github.com/ClickHouse/ClickHouse/pull/84732) ([Antonio Andelic](https://github.com/antonio2368)).
* Add missing support of `read_in_order_use_virtual_row` for `WHERE`. It allows to skip reading more parts for queries with filters that were not fully pushed to `PREWHERE`. [#84835](https://github.com/ClickHouse/ClickHouse/pull/84835) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Allows asynchronously iterating objects from Iceberg table without storing objects for each data file explicitly. [#85369](https://github.com/ClickHouse/ClickHouse/pull/85369) ([Daniil Ivanik](https://github.com/divanik)).
* Execute non-correlated `EXISTS` as a scalar subquery. This allows using a scalar subquery cache and constant-folding the result, which is helpful for indexes. For compatibility, the new setting `execute_exists_as_scalar_subquery=1` is added. [#85481](https://github.com/ClickHouse/ClickHouse/pull/85481) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
#### Improvement
* Add `database_replicated` settings defining the default values of DatabaseReplicatedSettings. If the setting is not present in the Replicated DB create query, the value from this setting is used. [#85127](https://github.com/ClickHouse/ClickHouse/pull/85127) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Made the table columns in the web UI (play) resizable. [#84012](https://github.com/ClickHouse/ClickHouse/pull/84012) ([Doron David](https://github.com/dorki)).
* Support compressed `.metadata.json` file via `iceberg_metadata_compression_method` setting. It supports all clickhouse compression methods. This closes [#84895](https://github.com/ClickHouse/ClickHouse/issues/84895). [#85196](https://github.com/ClickHouse/ClickHouse/pull/85196) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Show the number of ranges to be read in the output of `EXPLAIN indexes = 1`. [#79938](https://github.com/ClickHouse/ClickHouse/pull/79938) ([Christoph Wurm](https://github.com/cwurm)).
* Introduce settings to set ORC compression block size, and update its default value from 64KB to 256KB to keep consistent with spark or hive. [#80602](https://github.com/ClickHouse/ClickHouse/pull/80602) ([李扬](https://github.com/taiyang-li)).
* Add `columns_substreams.txt` file to Wide part to track all substreams stored in the part. It helps to track dynamic streams in JSON and Dynamic types and so avoid reading sample of these columns to get the list of dynamic streams (for example for columns sizes calculation). Also now all dynamic streams are reflected in `system.parts_columns`. [#81091](https://github.com/ClickHouse/ClickHouse/pull/81091) ([Pavel Kruglov](https://github.com/Avogar)).
* Add a CLI flag --show\_secrets to clickhouse format to hide sensitive data by default. [#81524](https://github.com/ClickHouse/ClickHouse/pull/81524) ([Nikolai Ryzhov](https://github.com/Dolaxom)).
* S3 read and write requests are throttled on the HTTP socket level (instead of whole S3 requests) to avoid issues with `max_remote_read_network_bandwidth_for_server` and `max_remote_write_network_bandwidth_for_server` throttling. [#81837](https://github.com/ClickHouse/ClickHouse/pull/81837) ([Sergei Trifonov](https://github.com/serxa)).
* Allow to mix different collations for the same column in different windows (for window functions). [#82877](https://github.com/ClickHouse/ClickHouse/pull/82877) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Add a tool to simulate, visualize and compare merge selectors. [#71496](https://github.com/ClickHouse/ClickHouse/pull/71496) ([Sergei Trifonov](https://github.com/serxa)).
* Add support of `remote*` table functions with parallel replicas if cluster is provided in `address_expression` argument. Also, fixes [#73295](https://github.com/ClickHouse/ClickHouse/issues/73295). [#82904](https://github.com/ClickHouse/ClickHouse/pull/82904) ([Igor Nikonov](https://github.com/devcrafter)).
* Set all log messages for writing backup files to TRACE. [#82907](https://github.com/ClickHouse/ClickHouse/pull/82907) ([Hans Krutzer](https://github.com/hkrutzer)).
* User-defined functions with unusual names and codecs can be formatted inconsistently by the SQL formatter. This closes [#83092](https://github.com/ClickHouse/ClickHouse/issues/83092). [#83644](https://github.com/ClickHouse/ClickHouse/pull/83644) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* You can now use Time and Time64 types inside the JSON type. [#83784](https://github.com/ClickHouse/ClickHouse/pull/83784) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Joins with parallel replicas now use the join logical step. In case of any issues with join queries using parallel replicas, try `SET query_plan_use_new_logical_join_step=0` and report an issue. [#83801](https://github.com/ClickHouse/ClickHouse/pull/83801) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix compatibility for cluster\_function\_process\_archive\_on\_multiple\_nodes. [#83968](https://github.com/ClickHouse/ClickHouse/pull/83968) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Support changing mv insert settings on `S3Queue` table level. Added new `S3Queue` level settings: `min_insert_block_size_rows_for_materialized_views` and `min_insert_block_size_bytes_for_materialized_views`. By default profile level settings will be used and `S3Queue` level settings will override those. [#83971](https://github.com/ClickHouse/ClickHouse/pull/83971) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Added profile event `MutationAffectedRowsUpperBound` that shows the number of affected rows in a mutation (e.g., the total number of rows that satisfy the condition in `ALTER UPDATE` or `ALTER DELETE` query. [#83978](https://github.com/ClickHouse/ClickHouse/pull/83978) ([Anton Popov](https://github.com/CurtizJ)).
* Use information from cgroup (if applicable, i.e. `memory_worker_use_cgroup` and cgroups are available) to adjust memory tracker (`memory_worker_correct_memory_tracker`). [#83981](https://github.com/ClickHouse/ClickHouse/pull/83981) ([Azat Khuzhin](https://github.com/azat)).
* MongoDB: Implicit parsing of strings to numeric types. Previously, if a string value was received from a MongoDB source for a numeric column in a ClickHouse table, an exception was thrown. Now, the engine attempts to parse the numeric value from the string automatically. Closes [#81167](https://github.com/ClickHouse/ClickHouse/issues/81167). [#84069](https://github.com/ClickHouse/ClickHouse/pull/84069) ([Kirill Nikiforov](https://github.com/allmazz)).
* Highlight digit groups in `Pretty` formats for `Nullable` numbers. [#84070](https://github.com/ClickHouse/ClickHouse/pull/84070) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Dashboard: the tooltip will not overflow the container at the top. [#84072](https://github.com/ClickHouse/ClickHouse/pull/84072) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Slightly better-looking dots on the dashboard. [#84074](https://github.com/ClickHouse/ClickHouse/pull/84074) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Dashboard now has a slightly better favicon. [#84076](https://github.com/ClickHouse/ClickHouse/pull/84076) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Web UI: Give browsers a chance to save the password. Also, it will remember the URL values. [#84087](https://github.com/ClickHouse/ClickHouse/pull/84087) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add support for applying extra ACL on specific Keeper nodes using `apply_to_children` config. [#84137](https://github.com/ClickHouse/ClickHouse/pull/84137) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix usage of "compact" Variant discriminators serialization in MergeTree. Perviously it wasn't used in some cases when it could be used. [#84141](https://github.com/ClickHouse/ClickHouse/pull/84141) ([Pavel Kruglov](https://github.com/Avogar)).
* Added a server setting, `logs_to_keep` to database replicated settings, that allows changing the default `logs_to_keep` parameter for replicated databases. Lower values reduce the number of ZNodes (especially if there are many databases), while higher values allow a missing replica to catch up after a longer period of time. [#84183](https://github.com/ClickHouse/ClickHouse/pull/84183) ([Alexey Khatskevich](https://github.com/Khatskevich)).
* Add a setting `json_type_escape_dots_in_keys` to escape dots in JSON keys during JSON type parsing. The setting is disabled by default. [#84207](https://github.com/ClickHouse/ClickHouse/pull/84207) ([Pavel Kruglov](https://github.com/Avogar)).
* Check if connection is cancelled before checking for EOF to prevent reading from closed connection. Fixes [#83893](https://github.com/ClickHouse/ClickHouse/issues/83893). [#84227](https://github.com/ClickHouse/ClickHouse/pull/84227) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Slightly better colors of text selection in Web UI. The difference is significant only for selected table cells in the dark mode. In previous versions, there was not enough contrast between the text and the selection background. [#84258](https://github.com/ClickHouse/ClickHouse/pull/84258) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Improved server shutdown handling for client connections by simplifying internal checks. [#84312](https://github.com/ClickHouse/ClickHouse/pull/84312) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Added a setting `delta_lake_enable_expression_visitor_logging` to turn off expression visitor logs as they can be too verbose even for test log level when debugging something. [#84315](https://github.com/ClickHouse/ClickHouse/pull/84315) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Cgroup-level and system-wide metrics are reported now altogether. Cgroup-level metrics have names `CGroup` and OS-level metrics (collected from procfs) have names `OS`. [#84317](https://github.com/ClickHouse/ClickHouse/pull/84317) ([Nikita Taranov](https://github.com/nickitat)).
* Slightly better charts in Web UI. Not much, but better. [#84326](https://github.com/ClickHouse/ClickHouse/pull/84326) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Change the default of the Replicated database setting `max_retries_before_automatic_recovery` to 10, so it will recover faster in some cases. [#84369](https://github.com/ClickHouse/ClickHouse/pull/84369) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Fix formatting of CREATE USER with query parameters (i.e. `CREATE USER {username:Identifier} IDENTIFIED WITH no_password`). [#84376](https://github.com/ClickHouse/ClickHouse/pull/84376) ([Azat Khuzhin](https://github.com/azat)).
* Introduce `backup_restore_s3_retry_initial_backoff_ms`, `backup_restore_s3_retry_max_backoff_ms`, `backup_restore_s3_retry_jitter_factor` to configure the S3 retry backoff strategy used during backup and restore operations. [#84421](https://github.com/ClickHouse/ClickHouse/pull/84421) ([Julia Kartseva](https://github.com/jkartseva)).
* S3Queue ordered mode fix: quit earlier if shutdown was called. [#84463](https://github.com/ClickHouse/ClickHouse/pull/84463) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Support iceberg writes to read from pyiceberg. [#84466](https://github.com/ClickHouse/ClickHouse/pull/84466) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Allow set values type casting when pushing down `IN` / `GLOBAL IN` filters over KeyValue storage primary keys (e.g., EmbeddedRocksDB, KeeperMap). [#84515](https://github.com/ClickHouse/ClickHouse/pull/84515) ([Eduard Karacharov](https://github.com/korowa)).
* Bump chdig to [25.7.1](https://github.com/azat/chdig/releases/tag/v25.7.1). [#84521](https://github.com/ClickHouse/ClickHouse/pull/84521) ([Azat Khuzhin](https://github.com/azat)).
* Low-level errors during UDF execution now fail with error code `UDF_EXECUTION_FAILED`, whereas previously different error codes could be returned. [#84547](https://github.com/ClickHouse/ClickHouse/pull/84547) ([Xu Jia](https://github.com/XuJia0210)).
* Add `get_acl` command to KeeperClient. [#84641](https://github.com/ClickHouse/ClickHouse/pull/84641) ([Antonio Andelic](https://github.com/antonio2368)).
* Adds snapshot version to data lake table engines. [#84659](https://github.com/ClickHouse/ClickHouse/pull/84659) ([Pete Hampton](https://github.com/pjhampton)).
* Add a dimensional metric for the size of `ConcurrentBoundedQueue`, labelled by the queue type (i.e. what the queue is there for) and queue id (i.e. randomly generated id for the current instance of the queue). [#84675](https://github.com/ClickHouse/ClickHouse/pull/84675) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* The `system.columns` table now provides `column` as an alias for the existing `name` column. [#84695](https://github.com/ClickHouse/ClickHouse/pull/84695) ([Yunchi Pang](https://github.com/yunchipang)).
* New MergeTree setting `search_orphaned_parts_drives` to limit scope to look for parts e.g. by disks with local metadata. [#84710](https://github.com/ClickHouse/ClickHouse/pull/84710) ([Ilya Golshtein](https://github.com/ilejn)).
* Add 4LW in Keeper, `lgrq`, for toggling request logging of received requests. [#84719](https://github.com/ClickHouse/ClickHouse/pull/84719) ([Antonio Andelic](https://github.com/antonio2368)).
* Match external auth forward\_headers in case-insensitive way. [#84737](https://github.com/ClickHouse/ClickHouse/pull/84737) ([ingodwerust](https://github.com/ingodwerust)).
* The `encrypt_decrypt` tool now supports encrypted ZooKeeper connections. [#84764](https://github.com/ClickHouse/ClickHouse/pull/84764) ([Roman Vasin](https://github.com/rvasin)).
* Add format string column to `system.errors`. This column is needed to group by the same error type in alerting rules. [#84776](https://github.com/ClickHouse/ClickHouse/pull/84776) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Updated `clickhouse-format` to accept `--highlight` as an alias for `--hilite`. - Updated `clickhouse-client` to accept `--hilite` as an alias for `--highlight`. - Updated `clickhouse-format` documentation to reflect the change. [#84806](https://github.com/ClickHouse/ClickHouse/pull/84806) ([Rishabh Bhardwaj](https://github.com/rishabh1815769)).
* Fix iceberg reading by field ids for complex types. [#84821](https://github.com/ClickHouse/ClickHouse/pull/84821) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Introduce a new `backup_slow_all_threads_after_retryable_s3_error` setting to reduce pressure on S3 during retry storms caused by errors such as `SlowDown`, by slowing down all threads once a single retryable error is observed. [#84854](https://github.com/ClickHouse/ClickHouse/pull/84854) ([Julia Kartseva](https://github.com/jkartseva)).
* Skip creating and renaming the old temp table of non-append RMV DDLs in Replicated DBs. [#84858](https://github.com/ClickHouse/ClickHouse/pull/84858) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Limit Keeper log entry cache size by number of entries using `keeper_server.coordination_settings.latest_logs_cache_entry_count_threshold` and `keeper_server.coordination_settings.commit_logs_cache_entry_count_threshold`. [#84877](https://github.com/ClickHouse/ClickHouse/pull/84877) ([Antonio Andelic](https://github.com/antonio2368)).
* Allow using `simdjson` on unsupported architectures (previously leads to `CANNOT_ALLOCATE_MEMORY` errors). [#84966](https://github.com/ClickHouse/ClickHouse/pull/84966) ([Azat Khuzhin](https://github.com/azat)).
* Async logging: Make limits tuneable and add introspection. [#85105](https://github.com/ClickHouse/ClickHouse/pull/85105) ([Raúl Marín](https://github.com/Algunenano)).
* Collect all removed objects to execute single object storage remove operation. [#85316](https://github.com/ClickHouse/ClickHouse/pull/85316) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Iceberg's current implementation of positional delete files keeps all data in RAM. This can be quite expensive if the positional delete files are large, which is often the case. My implementation keeps only the last row-group of Parquet delete files in RAM, which is significantly cheaper. [#85329](https://github.com/ClickHouse/ClickHouse/pull/85329) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* chdig: fix leftovers on the screen, fix crash after edit query in editor, search in `path` for `editor`, update to [25.8.1](https://github.com/azat/chdig/releases/tag/v25.8.1). [#85341](https://github.com/ClickHouse/ClickHouse/pull/85341) ([Azat Khuzhin](https://github.com/azat)).
* Add missing `partition_columns_in_data_file` to azure configuration. [#85373](https://github.com/ClickHouse/ClickHouse/pull/85373) ([Arthur Passos](https://github.com/arthurpassos)).
* Allow zero step in functions `timeSeries*ToGrid` This is part of [#75036](https://github.com/ClickHouse/ClickHouse/pull/75036). [#85390](https://github.com/ClickHouse/ClickHouse/pull/85390) ([Vitaly Baranov](https://github.com/vitlibar)).
* Added show\_data\_lake\_catalogs\_in\_system\_tables flag to manage adding data lake tables in system.tables. Resolves [#85384](https://github.com/ClickHouse/ClickHouse/issues/85384). [#85411](https://github.com/ClickHouse/ClickHouse/pull/85411) ([Smita Kulkarni](https://github.com/SmitaRKulkarni)).
* Added support for macro expansion in `remote_fs_zero_copy_zookeeper_path`. [#85437](https://github.com/ClickHouse/ClickHouse/pull/85437) ([Mikhail Koviazin](https://github.com/mkmkme)).
* AI in clickhouse-client will look slightly better. [#85447](https://github.com/ClickHouse/ClickHouse/pull/85447) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Enable trace\_log.symbolize for old deployments by default. [#85456](https://github.com/ClickHouse/ClickHouse/pull/85456) ([Azat Khuzhin](https://github.com/azat)).
* Support resolution of more cases for compound identifiers. Particularly, it improves the compatibility of `ARRAY JOIN` with the old analyzer. Introduce a new setting `analyzer_compatibility_allow_compound_identifiers_in_unflatten_nested` to keep the old behaviour. [#85492](https://github.com/ClickHouse/ClickHouse/pull/85492) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Ignore UNKNOWN\_DATABASE while obtaining table columns sizes for system.columns. [#85632](https://github.com/ClickHouse/ClickHouse/pull/85632) ([Azat Khuzhin](https://github.com/azat)).
* Added a limit (table setting `max_uncompressed_bytes_in_patches`) for total uncompressed bytes in patch parts. It prevents significant slowdowns of SELECT queries after lightweight updates and prevents possible misuse of lightweight updates. [#85641](https://github.com/ClickHouse/ClickHouse/pull/85641) ([Anton Popov](https://github.com/CurtizJ)).
* Add a `parameter` column to `system.grants` to determine source type for `GRANT READ/WRITE` and the table engine for `GRANT TABLE ENGINE`. [#85643](https://github.com/ClickHouse/ClickHouse/pull/85643) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* Fix parsing of a trailing comma in columns of the CREATE DICTIONARY query after a column with parameters, for example, Decimal(8). Closes [#85586](https://github.com/ClickHouse/ClickHouse/issues/85586). [#85653](https://github.com/ClickHouse/ClickHouse/pull/85653) ([Nikolay Degterinsky](https://github.com/evillique)).
* Support inner arrays for the function `nested`. [#85719](https://github.com/ClickHouse/ClickHouse/pull/85719) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* All the allocations done by external libraries are now visible to ClickHouse's memory tracker and accounted properly. This may result in "increased" reported memory usage for certain queries or failures with `MEMORY_LIMIT_EXCEEDED`. [#84082](https://github.com/ClickHouse/ClickHouse/pull/84082) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
#### Bug Fix (user-visible misbehavior in an official stable release)
* This pr fixes the metadata resolution when querying iceberg tables through rest catalog. ... [#80562](https://github.com/ClickHouse/ClickHouse/pull/80562) ([Saurabh Kumar Ojha](https://github.com/saurabhojha)).
* Fix markReplicasActive in DDLWorker and DatabaseReplicatedDDLWorker. [#81395](https://github.com/ClickHouse/ClickHouse/pull/81395) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Fix rollback of Dynamic column on parsing failure. [#82169](https://github.com/ClickHouse/ClickHouse/pull/82169) ([Pavel Kruglov](https://github.com/Avogar)).
* If function `trim` called with all-constant inputs now produces a constant output string. (Bug [#78796](https://github.com/ClickHouse/ClickHouse/issues/78796)). [#82900](https://github.com/ClickHouse/ClickHouse/pull/82900) ([Robert Schulze](https://github.com/rschu1ze)).
* Fix logical error with duplicate subqueries when `optimize_syntax_fuse_functions` is enabled, close [#75511](https://github.com/ClickHouse/ClickHouse/issues/75511). [#83300](https://github.com/ClickHouse/ClickHouse/pull/83300) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fixed incorrect result of queries with `WHERE ... IN ()` clause and enabled query condition cache (setting `use_query_condition_cache`). [#83445](https://github.com/ClickHouse/ClickHouse/pull/83445) ([LB7666](https://github.com/acking-you)).
* Historically, `gcs` function did not require any access to use. Now it will check `GRANT READ ON S3` permission for usage. Closes [#70567](https://github.com/ClickHouse/ClickHouse/issues/70567). [#83503](https://github.com/ClickHouse/ClickHouse/pull/83503) ([pufit](https://github.com/pufit)).
* Skip unavailable nodes during INSERT SELECT from s3Cluster() into replicated MergeTree. [#83676](https://github.com/ClickHouse/ClickHouse/pull/83676) ([Igor Nikonov](https://github.com/devcrafter)).
* Fix write with append (in MergeTree used for experimental transactions) with `plain_rewritable`/`plain` metadata types, previously they were simply ignored. [#83695](https://github.com/ClickHouse/ClickHouse/pull/83695) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Mask Avro schema registry authentication details to be not visible to user or in logs. [#83713](https://github.com/ClickHouse/ClickHouse/pull/83713) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Fix the issue where, if a MergeTree table is created with `add_minmax_index_for_numeric_columns=1` or `add_minmax_index_for_string_columns=1`, the index is later materialized during an ALTER operation, and it prevents the Replicated database from initializing correctly on a new replica. [#83751](https://github.com/ClickHouse/ClickHouse/pull/83751) ([Nikolay Degterinsky](https://github.com/evillique)).
* Fixed parquet writer outputting incorrect statistics (min/max) for Decimal types. [#83754](https://github.com/ClickHouse/ClickHouse/pull/83754) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix sort of NaN values in `LowCardinality(Float32|Float64|BFloat16)` type. [#83786](https://github.com/ClickHouse/ClickHouse/pull/83786) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* When restoring from backup, the definer user may not be backed up, which will cause the whole backup to be broken. To fix this, we postpone the permissions check on the target table's creation during restore and only check it during runtime. [#83818](https://github.com/ClickHouse/ClickHouse/pull/83818) ([pufit](https://github.com/pufit)).
* Fix crash in client due to connection left in disconnected state after bad INSERT. [#83842](https://github.com/ClickHouse/ClickHouse/pull/83842) ([Azat Khuzhin](https://github.com/azat)).
* Allow referencing any table in `view(...)` argument of `remote` table function with enabled analyzer. Fixes [#78717](https://github.com/ClickHouse/ClickHouse/issues/78717). Fixes [#79377](https://github.com/ClickHouse/ClickHouse/issues/79377). [#83844](https://github.com/ClickHouse/ClickHouse/pull/83844) ([Dmitry Novik](https://github.com/novikd)).
* Onprogress call in jsoneachrowwithprogress is synchronized with finalization. [#83879](https://github.com/ClickHouse/ClickHouse/pull/83879) ([Sema Checherinda](https://github.com/CheSema)).
* This closes [#81303](https://github.com/ClickHouse/ClickHouse/issues/81303). [#83892](https://github.com/ClickHouse/ClickHouse/pull/83892) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Fix colorSRGBToOKLCH/colorOKLCHToSRGB for mix of const and non-const args. [#83906](https://github.com/ClickHouse/ClickHouse/pull/83906) ([Azat Khuzhin](https://github.com/azat)).
* Fix writing JSON paths with NULL values in RowBinary format. [#83923](https://github.com/ClickHouse/ClickHouse/pull/83923) ([Pavel Kruglov](https://github.com/Avogar)).
* Overflow large values (>2106-02-07) when casting from Date to DateTime64 is fixed. [#83982](https://github.com/ClickHouse/ClickHouse/pull/83982) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Always apply `filesystem_prefetches_limit` (not only from `MergeTreePrefetchedReadPool`). [#83999](https://github.com/ClickHouse/ClickHouse/pull/83999) ([Azat Khuzhin](https://github.com/azat)).
* Fix rare bug when `MATERIALIZE COLUMN` query could lead to unexpected files in `checksums.txt` and eventually detached data parts. [#84007](https://github.com/ClickHouse/ClickHouse/pull/84007) ([alesapin](https://github.com/alesapin)).
* Fix the logical error `Expected single dictionary argument for function` while doing JOIN on an inequality condition when one of the columns is `LowCardinality` and the other is a constant. Closes [#81779](https://github.com/ClickHouse/ClickHouse/issues/81779). [#84019](https://github.com/ClickHouse/ClickHouse/pull/84019) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix crash with clickhouse client when used in interactive mode with syntax highlighting. [#84025](https://github.com/ClickHouse/ClickHouse/pull/84025) ([Bharat Nallan](https://github.com/bharatnc)).
* Fixed wrong results when the query condition cache is used in conjunction with recursive CTEs (issue [#81506](https://github.com/ClickHouse/ClickHouse/issues/81506)). [#84026](https://github.com/ClickHouse/ClickHouse/pull/84026) ([zhongyuankai](https://github.com/zhongyuankai)).
* Handle exceptions properly in periodic parts refresh. [#84083](https://github.com/ClickHouse/ClickHouse/pull/84083) ([Azat Khuzhin](https://github.com/azat)).
* Fix filter merging into JOIN condition in cases when equality operands have different types or they reference constants. Fixes [#83432](https://github.com/ClickHouse/ClickHouse/issues/83432). [#84145](https://github.com/ClickHouse/ClickHouse/pull/84145) ([Dmitry Novik](https://github.com/novikd)).
* Fix rare clickhouse crash when table has projection, `lightweight_mutation_projection_mode = 'rebuild'` and user execute lighweight delete which deletes ALL rows from any block in table. [#84158](https://github.com/ClickHouse/ClickHouse/pull/84158) ([alesapin](https://github.com/alesapin)).
* Fix deadlock caused by background cancellation checker thread. [#84203](https://github.com/ClickHouse/ClickHouse/pull/84203) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix infinite recursive analysis of invalid `WINDOW` definitions. Fixes [#83131](https://github.com/ClickHouse/ClickHouse/issues/83131). [#84242](https://github.com/ClickHouse/ClickHouse/pull/84242) ([Dmitry Novik](https://github.com/novikd)).
* Fixed a bug that was causing incorrect Bech32 Encoding and Decoding. The bug wasn't caught originally due to an online implementation of the algorithm used for testing having the same issue. [#84257](https://github.com/ClickHouse/ClickHouse/pull/84257) ([George Larionov](https://github.com/george-larionov)).
* Fixed incorrect construction of empty tuples in the `array()` function. This fixes [#84202](https://github.com/ClickHouse/ClickHouse/issues/84202). [#84297](https://github.com/ClickHouse/ClickHouse/pull/84297) ([Amos Bird](https://github.com/amosbird)).
* Fix `LOGICAL_ERROR` for queries with parallel replicas and multiple INNER joins followed by RIGHT join. Do not use parallel replicas for such queries. [#84299](https://github.com/ClickHouse/ClickHouse/pull/84299) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Previously, `set` indexes didn't consider `Nullable` columns while checking if granules passed the filter (issue [#75485](https://github.com/ClickHouse/ClickHouse/issues/75485)). [#84305](https://github.com/ClickHouse/ClickHouse/pull/84305) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Now ClickHouse read tables from Glue Catalog where table type specified in lower case. [#84316](https://github.com/ClickHouse/ClickHouse/pull/84316) ([alesapin](https://github.com/alesapin)).
* Do not try to substitute table functions to its cluster alternative in presence of a JOIN or subquery. [#84335](https://github.com/ClickHouse/ClickHouse/pull/84335) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fix logger usage in `IAccessStorage`. [#84365](https://github.com/ClickHouse/ClickHouse/pull/84365) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fixed a logical error in lightweight updates that update all columns in the table. [#84380](https://github.com/ClickHouse/ClickHouse/pull/84380) ([Anton Popov](https://github.com/CurtizJ)).
* Codec `DoubleDelta` codec can now only be applied to columns of numeric type. In particular `FixedString` columns can no longer be compressed using `DoubleDelta`. (fixes [#80220](https://github.com/ClickHouse/ClickHouse/issues/80220)). [#84383](https://github.com/ClickHouse/ClickHouse/pull/84383) ([Jimmy Aguilar Mena](https://github.com/Ergus)).
* The comparison against nan value was not using the correct ranges during `MinMax` index evaluation. [#84386](https://github.com/ClickHouse/ClickHouse/pull/84386) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Fix reading Variant column with lazy materialization. [#84400](https://github.com/ClickHouse/ClickHouse/pull/84400) ([Pavel Kruglov](https://github.com/Avogar)).
* Make `zoutofmemory` hardware error, otherwise it will throw logical error. see [https://github.com/clickhouse/clickhouse-core-incidents/issues/877](https://github.com/clickhouse/clickhouse-core-incidents/issues/877). [#84420](https://github.com/ClickHouse/ClickHouse/pull/84420) ([Han Fei](https://github.com/hanfei1991)).
* Fixed server crash when a user created with `no_password` attempts to login after the server setting `allow_no_password` was changed to 0. [#84426](https://github.com/ClickHouse/ClickHouse/pull/84426) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Fix out-of-order writes to Keeper changelog. Previously, we could have in-flight writes to changelog, but rollback could cause concurrent change of the destination file. This would lead to inconsistent logs, and possible data loss. [#84434](https://github.com/ClickHouse/ClickHouse/pull/84434) ([Antonio Andelic](https://github.com/antonio2368)).
* Now if all TTL are removed from table MergeTree will do nothing related to TTL. [#84441](https://github.com/ClickHouse/ClickHouse/pull/84441) ([alesapin](https://github.com/alesapin)).
* Parallel distributed INSERT SELECT with LIMIT was allowed which is not correct, it leads to data duplication in target table. [#84477](https://github.com/ClickHouse/ClickHouse/pull/84477) ([Igor Nikonov](https://github.com/devcrafter)).
* Fix pruning files by virtual column in data lakes. [#84520](https://github.com/ClickHouse/ClickHouse/pull/84520) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix leaks for keeper with rocksdb storage (iterators was not destroyed). [#84523](https://github.com/ClickHouse/ClickHouse/pull/84523) ([Azat Khuzhin](https://github.com/azat)).
* Fix ALTER MODIFY ORDER BY not validating TTL columns in sorting keys. TTL columns are now properly rejected when used in ORDER BY clauses during ALTER operations, preventing potential table corruption. [#84536](https://github.com/ClickHouse/ClickHouse/pull/84536) ([xiaohuanlin](https://github.com/xiaohuanlin)).
* Change pre-25.5 value of `allow_experimental_delta_kernel_rs` to `false` for compatibility. [#84587](https://github.com/ClickHouse/ClickHouse/pull/84587) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Stops taking schema from manifest files but stores relevant schemas for each snapshot independently. Infer relevant schema for each data file from its corresponding snapshot. Previous behaviour violated Iceberg specification for manifest files entries with existing status. [#84588](https://github.com/ClickHouse/ClickHouse/pull/84588) ([Daniil Ivanik](https://github.com/divanik)).
* Fixed issue where Keeper setting `rotate_log_storage_interval = 0` would cause ClickHouse to crash. (issue [#83975](https://github.com/ClickHouse/ClickHouse/issues/83975)). [#84637](https://github.com/ClickHouse/ClickHouse/pull/84637) ([George Larionov](https://github.com/george-larionov)).
* Fix logical error from S3Queue "Table is already registered". Closes [#84433](https://github.com/ClickHouse/ClickHouse/issues/84433). Broken after [https://github.com/ClickHouse/ClickHouse/pull/83530](https://github.com/ClickHouse/ClickHouse/pull/83530). [#84677](https://github.com/ClickHouse/ClickHouse/pull/84677) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Lock 'mutex' when getting zookeeper from 'view' in RefreshTask. [#84699](https://github.com/ClickHouse/ClickHouse/pull/84699) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Fix `CORRUPTED_DATA` error when lazy columns are used with external sort. [#84738](https://github.com/ClickHouse/ClickHouse/pull/84738) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Fix column pruning with delta-kernel in storage `DeltaLake`. Closes [#84543](https://github.com/ClickHouse/ClickHouse/issues/84543). [#84745](https://github.com/ClickHouse/ClickHouse/pull/84745) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Refresh credentials in delta-kernel in storage DeltaLake. [#84751](https://github.com/ClickHouse/ClickHouse/pull/84751) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix starting superfluous internal backups after connection problems. [#84755](https://github.com/ClickHouse/ClickHouse/pull/84755) ([Vitaly Baranov](https://github.com/vitlibar)).
* Fixed issue where querying a delayed remote source could result in vector out of bounds. [#84820](https://github.com/ClickHouse/ClickHouse/pull/84820) ([George Larionov](https://github.com/george-larionov)).
* The `ngram` and `no_op` tokenizers no longer crash the (experimental) text index for empty input tokens. [#84849](https://github.com/ClickHouse/ClickHouse/pull/84849) ([Robert Schulze](https://github.com/rschu1ze)).
* Fixed lightweight updates for tables with `ReplacingMergeTree` and `CollapsingMergeTree` engines. [#84851](https://github.com/ClickHouse/ClickHouse/pull/84851) ([Anton Popov](https://github.com/CurtizJ)).
* Correctly store all settings in table metadata for tables using object queue engine. [#84860](https://github.com/ClickHouse/ClickHouse/pull/84860) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix total watches count returned by Keeper. [#84890](https://github.com/ClickHouse/ClickHouse/pull/84890) ([Antonio Andelic](https://github.com/antonio2368)).
* Fixed lightweight updates for tables with `ReplicatedMergeTree` engine created on servers with a version lower than 25.7. [#84933](https://github.com/ClickHouse/ClickHouse/pull/84933) ([Anton Popov](https://github.com/CurtizJ)).
* Fixed lightweight updates for tables with non-replicated `MergeTree` engine after running a `ALTER TABLE ... REPLACE PARTITION` query. [#84941](https://github.com/ClickHouse/ClickHouse/pull/84941) ([Anton Popov](https://github.com/CurtizJ)).
* Fixes column name generation for boolean literals to use "true"/"false" instead of "1"/"0", preventing column name conflicts between boolean and integer literals in queries. [#84945](https://github.com/ClickHouse/ClickHouse/pull/84945) ([xiaohuanlin](https://github.com/xiaohuanlin)).
* Fix memory tracking drift from background schedule pool and executor. [#84946](https://github.com/ClickHouse/ClickHouse/pull/84946) ([Azat Khuzhin](https://github.com/azat)).
* Fix potential inaccurate sorting issues in the Merge table engine. [#85025](https://github.com/ClickHouse/ClickHouse/pull/85025) ([Xiaozhe Yu](https://github.com/wudidapaopao)).
* Implement missing APIs for DiskEncrypted. [#85028](https://github.com/ClickHouse/ClickHouse/pull/85028) ([Azat Khuzhin](https://github.com/azat)).
* Add a check if a correlated subquery is used in a distributed context to avoid a crash. Fixes [#82205](https://github.com/ClickHouse/ClickHouse/issues/82205). [#85030](https://github.com/ClickHouse/ClickHouse/pull/85030) ([Dmitry Novik](https://github.com/novikd)).
* Now Iceberg doesn't try to cache relevant snapshot version between select queries and always try to resolve snapshot honestly. Earlier attempt to cache iceberg snapshot led to problems with usage of Iceberg table with time travel. [#85038](https://github.com/ClickHouse/ClickHouse/pull/85038) ([Daniil Ivanik](https://github.com/divanik)).
* Fixed double-free in `AzureIteratorAsync`. [#85064](https://github.com/ClickHouse/ClickHouse/pull/85064) ([Nikita Taranov](https://github.com/nickitat)).
* Improve error message on attempt to create user identified with JWT. [#85072](https://github.com/ClickHouse/ClickHouse/pull/85072) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fixed cleanup of patch parts in `ReplicatedMergeTree`. Previously, the result of a lightweight update may temporarily not be visible on the replica until the merged or mutated part that materializes the patch parts is downloaded from another replica. [#85121](https://github.com/ClickHouse/ClickHouse/pull/85121) ([Anton Popov](https://github.com/CurtizJ)).
* Fixing illegal\_type\_of\_argument in mv when types are different. [#85135](https://github.com/ClickHouse/ClickHouse/pull/85135) ([Sema Checherinda](https://github.com/CheSema)).
* Fix segfault in delta-kernel implementation. [#85160](https://github.com/ClickHouse/ClickHouse/pull/85160) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix recovering replicated databases when moving the metadata file takes a long time. [#85177](https://github.com/ClickHouse/ClickHouse/pull/85177) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Fix `Not-ready Set` for `IN (subquery)` inside `additional_table_filters expression` setting. [#85210](https://github.com/ClickHouse/ClickHouse/pull/85210) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Get rid of unnecessary `getStatus()` calls during SYSTEM DROP REPLICA queries. Fixes the case when a table is dropped in the background, and the `Shutdown for storage is called` exception is thrown. [#85220](https://github.com/ClickHouse/ClickHouse/pull/85220) ([Nikolay Degterinsky](https://github.com/evillique)).
* Fix race in `DeltaLake` engine delta-kernel implementation. [#85221](https://github.com/ClickHouse/ClickHouse/pull/85221) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix reading partitioned data with disabled delta-kernel in `DeltaLake` engine. It was broken in 25.7 ([https://github.com/ClickHouse/ClickHouse/pull/81136](https://github.com/ClickHouse/ClickHouse/pull/81136)). [#85223](https://github.com/ClickHouse/ClickHouse/pull/85223) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Added missing table name length checks in CREATE OR REPLACE and RENAME queries. [#85326](https://github.com/ClickHouse/ClickHouse/pull/85326) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix the creation of RMV on a new replica of the Replicated database if DEFINER is dropped. [#85327](https://github.com/ClickHouse/ClickHouse/pull/85327) ([Nikolay Degterinsky](https://github.com/evillique)).
* Fix iceberg writes for complex types. [#85330](https://github.com/ClickHouse/ClickHouse/pull/85330) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Writing lower and upper bounds are not supported for complex types. [#85332](https://github.com/ClickHouse/ClickHouse/pull/85332) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Fix logical error while reading from object storage functions through Distributed table or remote table function. Fixes: [#84658](https://github.com/ClickHouse/ClickHouse/issues/84658), Fixes [#85173](https://github.com/ClickHouse/ClickHouse/issues/85173), Fixes [#52022](https://github.com/ClickHouse/ClickHouse/issues/52022). [#85359](https://github.com/ClickHouse/ClickHouse/pull/85359) ([alesapin](https://github.com/alesapin)).
* Fix backup of parts with broken projections. [#85362](https://github.com/ClickHouse/ClickHouse/pull/85362) ([Antonio Andelic](https://github.com/antonio2368)).
* Forbid using `_part_offset` column in projection in releases until it is stabilized. [#85372](https://github.com/ClickHouse/ClickHouse/pull/85372) ([Sema Checherinda](https://github.com/CheSema)).
* Fix crash and data corruption during ALTER UPDATE for JSON. [#85383](https://github.com/ClickHouse/ClickHouse/pull/85383) ([Pavel Kruglov](https://github.com/Avogar)).
* Queries with parallel replicas which uses reading reverse in order optimization can produce incorrect result. [#85406](https://github.com/ClickHouse/ClickHouse/pull/85406) ([Igor Nikonov](https://github.com/devcrafter)).
* Fix possible UB (crashes) in case of MEMORY\_LIMIT\_EXCEEDED during String deserialization. [#85440](https://github.com/ClickHouse/ClickHouse/pull/85440) ([Azat Khuzhin](https://github.com/azat)).
* Fix incorrect metrics KafkaAssignedPartitions and KafkaConsumersWithAssignment. [#85494](https://github.com/ClickHouse/ClickHouse/pull/85494) ([Ilya Golshtein](https://github.com/ilejn)).
* Fixed processed bytes stat being underestimated when PREWHERE (explicit or automatic) is used. [#85495](https://github.com/ClickHouse/ClickHouse/pull/85495) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix early return condition for S3 request rate slowdown: require either s3\_slow\_all\_threads\_after\_network\_error or backup\_slow\_all\_threads\_after\_retryable\_s3\_error to be true to enable slowdown behavior when all threads are paused due to a retryable error, instead of requiring both. [#85505](https://github.com/ClickHouse/ClickHouse/pull/85505) ([Julia Kartseva](https://github.com/jkartseva)).
* This pr fixes the metadata resolution when querying iceberg tables through rest catalog. ... [#85531](https://github.com/ClickHouse/ClickHouse/pull/85531) ([Saurabh Kumar Ojha](https://github.com/saurabhojha)).
* Fixed rare crash in asynchronous inserts that change settings `log_comment` or `insert_deduplication_token`. [#85540](https://github.com/ClickHouse/ClickHouse/pull/85540) ([Anton Popov](https://github.com/CurtizJ)).
* Parameters like date\_time\_input\_format were ignored when using HTTP with multipart/form-data. [#85570](https://github.com/ClickHouse/ClickHouse/pull/85570) ([Sema Checherinda](https://github.com/CheSema)).
* Fix secrets masking in icebergS3Cluster and icebergAzureCluster table functions. [#85658](https://github.com/ClickHouse/ClickHouse/pull/85658) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* Fix precision loss in `JSONExtract` when converting JSON numbers to Decimal types. Now numeric JSON values preserve their exact decimal representation, avoiding floating-point rounding errors. [#85665](https://github.com/ClickHouse/ClickHouse/pull/85665) ([ssive7b](https://github.com/ssive7b)).
* Fixed `LOGICAL_ERROR` when using `COMMENT COLUMN IF EXISTS` in the same `ALTER` statement after `DROP COLUMN`. The `IF EXISTS` clause now correctly skips the comment operation when the column has been dropped within the same statement. [#85688](https://github.com/ClickHouse/ClickHouse/pull/85688) ([xiaohuanlin](https://github.com/xiaohuanlin)).
* Fix reading count from cache for delta lake. [#85704](https://github.com/ClickHouse/ClickHouse/pull/85704) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix coalescing merge tree segfault for large strings. This closes [#84582](https://github.com/ClickHouse/ClickHouse/issues/84582). [#85709](https://github.com/ClickHouse/ClickHouse/pull/85709) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Update metadata timestamp in iceberg writes. [#85711](https://github.com/ClickHouse/ClickHouse/pull/85711) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Using `distributed_depth` as an indicator of \*Cluster function was incorrect and may lead to data duplication; use `client_info.collaborate_with_initiator` instead. [#85734](https://github.com/ClickHouse/ClickHouse/pull/85734) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Spark can't read position delete files. [#85762](https://github.com/ClickHouse/ClickHouse/pull/85762) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Fix send\_logs\_source\_regexp (after async logging refactoring in [#85105](https://github.com/ClickHouse/ClickHouse/issues/85105)). [#85797](https://github.com/ClickHouse/ClickHouse/pull/85797) ([Azat Khuzhin](https://github.com/azat)).
* Fix possible inconsistency for dictionaries with update\_field on MEMORY\_LIMIT\_EXCEEDED errors. [#85807](https://github.com/ClickHouse/ClickHouse/pull/85807) ([Azat Khuzhin](https://github.com/azat)).
* Support global constants from `WITH` statement for the parallel distributed `INSERT SELECT` with the `Distributed` destination table. Before, the query could throw an `Unknown expression identifier` error. [#85811](https://github.com/ClickHouse/ClickHouse/pull/85811) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Mask credentials for `deltaLakeAzure`, `deltaLakeCluster`, `icebergS3Cluster` and `icebergAzureCluster`. [#85889](https://github.com/ClickHouse/ClickHouse/pull/85889) ([Julian Maicher](https://github.com/jmaicher)).
* Fix logical error on attempt to `CREATE ... AS (SELECT * FROM s3Cluster(...))` with `DatabaseReplicated`. [#85904](https://github.com/ClickHouse/ClickHouse/pull/85904) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fixes HTTP requests made by the `url()` table function to properly include port numbers in the Host header when accessing non-standard ports. This resolves authentication failures when using presigned URLs with S3-compatible services like MinIO running on custom ports, which is common in development environments. (Fixes [#85898](https://github.com/ClickHouse/ClickHouse/issues/85898)). [#85921](https://github.com/ClickHouse/ClickHouse/pull/85921) ([Tom Quist](https://github.com/tomquist)).
* Now unity catalog will ignore schemas with weird data types in case of non-delta tables. Fixes [#85699](https://github.com/ClickHouse/ClickHouse/issues/85699). [#85950](https://github.com/ClickHouse/ClickHouse/pull/85950) ([alesapin](https://github.com/alesapin)).
* Fix nullability of fields in iceberg. [#85977](https://github.com/ClickHouse/ClickHouse/pull/85977) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Fixed a bug in `Replicated` database recovery: if a table name contains the `%` symbol, it could re-create the table with a different name during recovery. [#85987](https://github.com/ClickHouse/ClickHouse/pull/85987) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Fix backup restores failing due to `BACKUP_ENTRY_NOT_FOUND` error when restoring an empty `Memory` table. [#86012](https://github.com/ClickHouse/ClickHouse/pull/86012) ([Julia Kartseva](https://github.com/jkartseva)).
* Add checks for sharding\_key during ALTER of the Distributed table. Previously incorrect ALTER would break the table definition and server restart. [#86015](https://github.com/ClickHouse/ClickHouse/pull/86015) ([Nikolay Degterinsky](https://github.com/evillique)).
* Don't create empty iceberg delete file. [#86061](https://github.com/ClickHouse/ClickHouse/pull/86061) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Fix large setting values breaking S3Queue tables and replica restart. [#86074](https://github.com/ClickHouse/ClickHouse/pull/86074) ([Nikolay Degterinsky](https://github.com/evillique)).
#### Build/Testing/Packaging Improvement
* Use encrypted disks for tests with S3 by default. [#59898](https://github.com/ClickHouse/ClickHouse/pull/59898) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Use `clickhouse` binary in integrations tests to get unstripped debug symbols. [#83779](https://github.com/ClickHouse/ClickHouse/pull/83779) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
* Bumped the internal libxml2 from 2.14.4 to 2.14.5. [#84230](https://github.com/ClickHouse/ClickHouse/pull/84230) ([Robert Schulze](https://github.com/rschu1ze)).
* Bumped internal curl from 8.14.0 to 8.15.0. [#84231](https://github.com/ClickHouse/ClickHouse/pull/84231) ([Robert Schulze](https://github.com/rschu1ze)).
* Now we use less memory for caches in CI and have better tests for eviction. [#84676](https://github.com/ClickHouse/ClickHouse/pull/84676) ([alesapin](https://github.com/alesapin)).
ClickHouse release 25.7, 2025-07-24
#### Backward Incompatible Change
* Changes to `extractKeyValuePairs` function: introduce a new argument `unexpected_quoting_character_strategy` that controls what happens when a `quoting_character` is unexpectedly found when reading a non quoted key or value. The value can be one of: `invalid`, `accept` or `promote`. Invalid will discard the key and go back to waiting key state. Accept will treat it as part of the key. Promote will discard previous character and start parsing as a quoted key. In addition, after parsing a quoted value, only parse the next key if a pair delimiter is found. [#80657](https://github.com/ClickHouse/ClickHouse/pull/80657) ([Arthur Passos](https://github.com/arthurpassos)).
* Support zero-byte match in `countMatches` function. Users who like to retain the old behavior can enable setting `count_matches_stop_at_empty_match`. [#81676](https://github.com/ClickHouse/ClickHouse/pull/81676) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Use server-wide throttlers for local (`max_local_read_bandwidth_for_server` and `max_local_write_bandwidth_for_server`) and remote (`max_remote_read_network_bandwidth_for_server` and `max_remote_write_network_bandwidth_for_server`) when generating BACKUPs in addition to their dedicated server settings (`max_backup_bandwidth_for_server`, `max_mutations_bandwidth_for_server` and `max_merges_bandwidth_for_server`). [#81753](https://github.com/ClickHouse/ClickHouse/pull/81753) ([Sergei Trifonov](https://github.com/serxa)).
* Forbid the creation of a table without insertable columns. [#81835](https://github.com/ClickHouse/ClickHouse/pull/81835) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Parallelize cluster functions by files within archives. In previous versions, the whole archive (such as zip, tar, or 7z) was a unit of work. Added a new setting `cluster_function_process_archive_on_multiple_nodes`, by default equal to `true`. If set to `true`, increases performance of processing archives in cluster functions. Should be set to `false` for compatibility and to avoid errors during upgrade to 25.7+ if using cluster functions with archives on earlier versions. [#82355](https://github.com/ClickHouse/ClickHouse/pull/82355) ([Kseniia Sumarokova](https://github.com/kssenii)).
* `SYSTEM RESTART REPLICAS` query led to the wakeup of tables in the Lazy database, even without access to that database, and it happened while these tables were being concurrently dropped. Note: Now `SYSTEM RESTART REPLICAS` will only restart replicas in the databases where you have permission to `SHOW TABLES`, which is natural. [#83321](https://github.com/ClickHouse/ClickHouse/pull/83321) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
#### New Feature
* Added support for lightweight updates for `MergeTree`-family tables. Lightweight updates can be used by a new syntax: `UPDATE SET col1 = val1, col2 = val2, ... WHERE `. Added implementation of lightweight deletes via lightweight updates. It can be enabled by setting `lightweight_delete_mode = 'lightweight_update'`. [#82004](https://github.com/ClickHouse/ClickHouse/pull/82004) ([Anton Popov](https://github.com/CurtizJ)).
* Support complex types in Iceberg schema evolution. [#73714](https://github.com/ClickHouse/ClickHouse/pull/73714) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Introduce support for INSERTs into Iceberg tables. [#82692](https://github.com/ClickHouse/ClickHouse/pull/82692) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Read Iceberg data files by field ids. This improves compatibility with Iceberg: the fields can be renamed in the metadata while being mapped to the different names in the underlying Parquet files. This closes [#83065](https://github.com/ClickHouse/ClickHouse/issues/83065). [#83653](https://github.com/ClickHouse/ClickHouse/pull/83653) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Now clickhouse supports compressed `metadata.json` files for Iceberg. Fixes [#70874](https://github.com/ClickHouse/ClickHouse/issues/70874). [#81451](https://github.com/ClickHouse/ClickHouse/pull/81451) ([alesapin](https://github.com/alesapin)).
* Support `TimestampTZ` in Glue catalog. This closes [#81654](https://github.com/ClickHouse/ClickHouse/issues/81654). [#83132](https://github.com/ClickHouse/ClickHouse/pull/83132) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Add AI-powered SQL generation to ClickHouse client. You can now generate SQL queries from natural language descriptions by prefixing their query with `??`. Supports OpenAI and Anthropic providers with automatic schema discovery. [#83314](https://github.com/ClickHouse/ClickHouse/pull/83314) ([Kaushik Iska](https://github.com/iskakaushik)).
* Add a function to write Geo types into WKB format. [#82935](https://github.com/ClickHouse/ClickHouse/pull/82935) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Introduced two new access types: `READ` and `WRITE` for sources and deprecates all previous access types related to sources. Before `GRANT S3 ON *.* TO user`, now: `GRANT READ, WRITE ON S3 TO user`. This also allows to separate `READ` and `WRITE` permissions for sources, e.g.: `GRANT READ ON * TO user`, `GRANT WRITE ON S3 TO user`. The feature is controlled by a setting `access_control_improvements.enable_read_write_grants` and disabled by default. [#73659](https://github.com/ClickHouse/ClickHouse/pull/73659) ([pufit](https://github.com/pufit)).
* NumericIndexedVector: new vector data-structure backed by bit-sliced, Roaring-bitmap compression, together with more than 20 functions for building, analysing and point-wise arithmetic. Can cut storage and speed up joins, filters and aggregations on sparse data. Implements [#70582](https://github.com/ClickHouse/ClickHouse/issues/70582) and [“Large-Scale Metric Computation in Online Controlled Experiment Platform” paper](https://arxiv.org/abs/2405.08411) by T. Xiong and Y. Wang from VLDB 2024. [#74193](https://github.com/ClickHouse/ClickHouse/pull/74193) ([FriendLey](https://github.com/FriendLey)).
* The workload setting `max_waiting_queries` is now supported. It can be used to limit the size of the query queue. If the limit is reached, all subsequent queries will be terminated with the `SERVER_OVERLOADED` error. [#81250](https://github.com/ClickHouse/ClickHouse/pull/81250) ([Oleg Doronin](https://github.com/dorooleg)).
* Add financial functions: `financialInternalRateOfReturnExtended` (`XIRR`), `financialInternalRateOfReturn` (`IRR`), `financialNetPresentValueExtended` (`XNPV`), `financialNetPresentValue` (`NPV`). [#81599](https://github.com/ClickHouse/ClickHouse/pull/81599) ([Joanna Hulboj](https://github.com/jh0x)).
* Add the geospatial functions `polygonsIntersectCartesian` and `polygonsIntersectSpherical` to check if two polygons intersect. [#81882](https://github.com/ClickHouse/ClickHouse/pull/81882) ([Paul Lamb](https://github.com/plamb)).
* Support `_part_granule_offset` virtual column in MergeTree-family tables. This column indicates the zero-based index of the granule/mark each row belongs to within its data part. This addresses [#79572](https://github.com/ClickHouse/ClickHouse/issues/79572). [#82341](https://github.com/ClickHouse/ClickHouse/pull/82341) ([Amos Bird](https://github.com/amosbird)). [#82341](https://github.com/ClickHouse/ClickHouse/pull/82341) ([Amos Bird](https://github.com/amosbird))
* Added SQL functions `colorSRGBToOkLCH` and `colorOkLCHToSRGB` for converting colours between the sRGB and OkLCH colour spaces. [#83679](https://github.com/ClickHouse/ClickHouse/pull/83679) ([Fgrtue](https://github.com/Fgrtue)).
* Allow parameters in `CREATE USER` queries for usernames. [#81387](https://github.com/ClickHouse/ClickHouse/pull/81387) ([Diskein](https://github.com/Diskein)).
* The `system.formats` table now contains extended information about formats, such as HTTP content type, the capabilities of schema inference, etc. [#81505](https://github.com/ClickHouse/ClickHouse/pull/81505) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
#### Experimental Feature
* Added functions `searchAny` and `searchAll` which are general purpose tools to search text indexes. [#80641](https://github.com/ClickHouse/ClickHouse/pull/80641) ([Elmi Ahmadov](https://github.com/ahmadov)).
* The text index now supports the new `split` tokenizer. [#81752](https://github.com/ClickHouse/ClickHouse/pull/81752) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Changed the default index granularity value for `text` indexes to 64. This improves the expected performance for the average test query in internal benchmarks. [#82162](https://github.com/ClickHouse/ClickHouse/pull/82162) ([Jimmy Aguilar Mena](https://github.com/Ergus)).
* The 256-bit bitmap stores the outgoing labels of a state ordered, but outgoing states are saved into disk in the order they appear in the hash table. Therefore, a label would point to a wrong next state while reading from disk. [#82783](https://github.com/ClickHouse/ClickHouse/pull/82783) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Enable zstd compression for FST tree blob in text indices. [#83093](https://github.com/ClickHouse/ClickHouse/pull/83093) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Promote vector similarity index to beta. Introduced alias setting `enable_vector_similarity_index` which must be enabled to use the vector similarity index. [#83459](https://github.com/ClickHouse/ClickHouse/pull/83459) ([Robert Schulze](https://github.com/rschu1ze)).
* Removed experimental `send_metadata` logic related to experimental zero-copy replication. It wasn't ever used and nobody supports this code. Since there were even no tests related to it, there is a high chance that it's broken long time ago. [#82508](https://github.com/ClickHouse/ClickHouse/pull/82508) ([alesapin](https://github.com/alesapin)).
* Integrate `StorageKafka2` to `system.kafka_consumers`. [#82652](https://github.com/ClickHouse/ClickHouse/pull/82652) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Estimate complex CNF/DNF, for example, `(a < 1 and a > 0) or b = 3`, by statistics. [#82663](https://github.com/ClickHouse/ClickHouse/pull/82663) ([Han Fei](https://github.com/hanfei1991)).
#### Performance Improvement
* Introduce async logging. When logs are output to a slow device, it no longer delays queries. [#82516](https://github.com/ClickHouse/ClickHouse/pull/82516) ([Raúl Marín](https://github.com/Algunenano)). Limit the max number of entries that are hold in the queue. [#83214](https://github.com/ClickHouse/ClickHouse/pull/83214) ([Raúl Marín](https://github.com/Algunenano)).
* Parallel distributed INSERT SELECT is enabled by default in mode where INSERT SELECT executed on each shard independently, see `parallel_distributed_insert_select` setting. [#83040](https://github.com/ClickHouse/ClickHouse/pull/83040) ([Igor Nikonov](https://github.com/devcrafter)).
* When the aggregation query contains only a single `count()` function on a not-`Nullable` column, the aggregation logic is fully inlined during hash table probing. This avoids allocating and maintaining any aggregation state, significantly reducing memory usage and CPU overhead. This partially addresses [#81982](https://github.com/ClickHouse/ClickHouse/issues/81982). [#82104](https://github.com/ClickHouse/ClickHouse/pull/82104) ([Amos Bird](https://github.com/amosbird)).
* Performance of `HashJoin` optimised by removing the additional loop over hash maps in the typical case of only one key column, also `null_map` and `join_mask` checks are eliminated when they're always `true`/`false`. [#82308](https://github.com/ClickHouse/ClickHouse/pull/82308) ([Nikita Taranov](https://github.com/nickitat)).
* Trivial optimization for `-If` combinator. [#78454](https://github.com/ClickHouse/ClickHouse/pull/78454) ([李扬](https://github.com/taiyang-li)).
* Vector search queries using a vector similarity index complete with lower latency due to reduced storage reads and reduced CPU usage. [#79103](https://github.com/ClickHouse/ClickHouse/pull/79103) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Respect `merge_tree_min_{rows,bytes}_for_seek` in `filterPartsByQueryConditionCache` to align it with other methods filtering by indexes. [#80312](https://github.com/ClickHouse/ClickHouse/pull/80312) ([李扬](https://github.com/taiyang-li)).
* Make the pipeline after the `TOTALS` step multithreaded. [#80331](https://github.com/ClickHouse/ClickHouse/pull/80331) ([UnamedRus](https://github.com/UnamedRus)).
* Fix filter by key for `Redis` and `KeeperMap` storages. [#81833](https://github.com/ClickHouse/ClickHouse/pull/81833) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Add new setting `min_joined_block_size_rows` (analogous to `min_joined_block_size_bytes`; defaults to 65409) to control the minimum block size (in rows) for JOIN input and output blocks (if the join algorithm supports it). Small blocks will be squashed. [#81886](https://github.com/ClickHouse/ClickHouse/pull/81886) ([Nikita Taranov](https://github.com/nickitat)).
* `ATTACH PARTITION` no longer leads to the dropping of all caches. [#82377](https://github.com/ClickHouse/ClickHouse/pull/82377) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Optimize the generated plan for correlated subqueries by removing redundant JOIN operations using equivalence classes. If there are equivalent expressions for all correlated columns, `CROSS JOIN` is not produced if `query_plan_correlated_subqueries_use_substitution` setting is enabled. [#82435](https://github.com/ClickHouse/ClickHouse/pull/82435) ([Dmitry Novik](https://github.com/novikd)).
* Read only required columns in correlated subquery when it appears to be an argument of function `EXISTS`. [#82443](https://github.com/ClickHouse/ClickHouse/pull/82443) ([Dmitry Novik](https://github.com/novikd)).
* Speedup comparisons of query trees during the query analysis a bit. [#82617](https://github.com/ClickHouse/ClickHouse/pull/82617) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Add alignment in the Counter of ProfileEvents to reduce false sharing. [#82697](https://github.com/ClickHouse/ClickHouse/pull/82697) ([Jiebin Sun](https://github.com/jiebinn)).
* The optimizations for `null_map` and `JoinMask` from [#82308](https://github.com/ClickHouse/ClickHouse/issues/82308) were applied to the case of JOIN with multiple disjuncts. Also, the `KnownRowsHolder` data structure was optimized. [#83041](https://github.com/ClickHouse/ClickHouse/pull/83041) ([Nikita Taranov](https://github.com/nickitat)).
* Plain `std::vector` is used for join flags to avoid calculating a hash on each access to flags. [#83043](https://github.com/ClickHouse/ClickHouse/pull/83043) ([Nikita Taranov](https://github.com/nickitat)).
* Don't pre-allocate memory for result columns beforehand when `HashJoin` uses `lazy` output mode. It is suboptimal, especially when the number of matches is low. Moreover, we know the exact amount of matches after joining is done, so we can preallocate more precisely. [#83304](https://github.com/ClickHouse/ClickHouse/pull/83304) ([Nikita Taranov](https://github.com/nickitat)).
* Minimize memory copy in port headers during pipeline construction. Original [PR](https://github.com/ClickHouse/ClickHouse/pull/70105) by [heymind](https://github.com/heymind). [#83381](https://github.com/ClickHouse/ClickHouse/pull/83381) ([Raúl Marín](https://github.com/Algunenano)).
* Improve the startup of clickhouse-keeper when it uses rocksdb storage. [#83390](https://github.com/ClickHouse/ClickHouse/pull/83390) ([Antonio Andelic](https://github.com/antonio2368)).
* Avoid holding the lock while creating storage snapshot data to reduce lock contention with high concurrent load. [#83510](https://github.com/ClickHouse/ClickHouse/pull/83510) ([Duc Canh Le](https://github.com/canhld94)).
* Improved performance of the `ProtobufSingle` input format by reusing the serializer when no parsing errors occur. [#83613](https://github.com/ClickHouse/ClickHouse/pull/83613) ([Eduard Karacharov](https://github.com/korowa)).
* Improve the performance of pipeline building that speeds up short queries. [#83631](https://github.com/ClickHouse/ClickHouse/pull/83631) ([Raúl Marín](https://github.com/Algunenano)).
* Optimize `MergeTreeReadersChain::getSampleBlock` that speeds up short queries. [#83875](https://github.com/ClickHouse/ClickHouse/pull/83875) ([Raúl Marín](https://github.com/Algunenano)).
* Speedup tables listing in data catalogs by asynchronous requests. [#81084](https://github.com/ClickHouse/ClickHouse/pull/81084) ([alesapin](https://github.com/alesapin)).
* Introduce jitter to the S3 retry mechanism when the `s3_slow_all_threads_after_network_error` configuration is enabled. [#81849](https://github.com/ClickHouse/ClickHouse/pull/81849) ([zoomxi](https://github.com/zoomxi)).
#### Improvement
* Color parenthesis in multiple colors for better readability. [#82538](https://github.com/ClickHouse/ClickHouse/pull/82538) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Highlight metacharacters in LIKE/REGEXP patterns as you type. We already have it in `clickhouse-format` and in the echo in `clickhouse-client`, but now it is done in the command prompt as well. [#82871](https://github.com/ClickHouse/ClickHouse/pull/82871) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Highlighting in `clickhouse-format` and in the client's echo will work in the same way as the highlighting in the command line prompt. [#82874](https://github.com/ClickHouse/ClickHouse/pull/82874) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Now `plain_rewritable` disks are allowed as disks for database metadata. Implement methods `moveFile` and `replaceFile` in `plain_rewritable` to support it as a database disk. [#79424](https://github.com/ClickHouse/ClickHouse/pull/79424) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Allow backups for `PostgreSQL`, `MySQL` and `DataLake` databases. A backup of such a database would only save the definition and not the data inside of it. [#79982](https://github.com/ClickHouse/ClickHouse/pull/79982) ([Nikolay Degterinsky](https://github.com/evillique)).
* Setting `allow_experimental_join_condition` marked as obsolete, because it is now always allowed. [#80566](https://github.com/ClickHouse/ClickHouse/pull/80566) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Add pressure metrics to ClickHouse async metrics. [#80779](https://github.com/ClickHouse/ClickHouse/pull/80779) ([Xander Garbett](https://github.com/Garbett1)).
* Added metrics `MarkCacheEvictedBytes`, `MarkCacheEvictedMarks`, `MarkCacheEvictedFiles` for tracking evictions from the mark cache. (issue [#60989](https://github.com/ClickHouse/ClickHouse/issues/60989)). [#80799](https://github.com/ClickHouse/ClickHouse/pull/80799) ([Shivji Kumar Jha](https://github.com/shiv4289)).
* Support writing Parquet enum as byte array as the [spec](https://github.com/apache/parquet-format/blob/master/LogicalTypes.md#enum) dictates. [#81090](https://github.com/ClickHouse/ClickHouse/pull/81090) ([Arthur Passos](https://github.com/arthurpassos)).
* An improvement for `DeltaLake` table engine: delta-kernel-rs has `ExpressionVisitor` API which is implemented in this PR and is applied to partition column expressions transform (it will replace an old deprecated within the delta-kernel-rs way, which was used before in our code). In the future this `ExpressionVisitor` will also allow to implement statistics based pruning and some delta-lake proprietary features. Additionally the purpose of this change is to support partition pruning in `DeltaLakeCluster` table engine (the result of a parsed expression - ActionsDAG - will be serialized and sent from the initiator along with the data path, because this kind of information, which is needed for pruning, is only available as meta information on data files listing, which is done by initiator only, but it has to be applied to data on each reading server). [#81136](https://github.com/ClickHouse/ClickHouse/pull/81136) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Preserve element names when deriving supertypes for named tuples. [#81345](https://github.com/ClickHouse/ClickHouse/pull/81345) ([lgbo](https://github.com/lgbo-ustc)).
* Count consumed messages manually to avoid depending on previous committed offset in StorageKafka2. [#81662](https://github.com/ClickHouse/ClickHouse/pull/81662) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Added `clickhouse-keeper-utils`, a new command-line tool for managing and analyzing ClickHouse Keeper data. The tool supports dumping state from snapshots and changelogs, analyzing changelog files, and extracting specific log ranges. [#81677](https://github.com/ClickHouse/ClickHouse/pull/81677) ([Antonio Andelic](https://github.com/antonio2368)).
* The total and per-user network throttlers are never reset, which ensures that `max_network_bandwidth_for_all_users` and `max_network_bandwidth_for_all_users` limits are never exceeded. [#81729](https://github.com/ClickHouse/ClickHouse/pull/81729) ([Sergei Trifonov](https://github.com/serxa)).
* Support writing geoparquets as output format. [#81784](https://github.com/ClickHouse/ClickHouse/pull/81784) ([Konstantin Vedernikov](https://github.com/scanhex12)).
* Forbid to start `RENAME COLUMN` alter mutation if it will rename some column that right now affected by incomplete data mutation. [#81823](https://github.com/ClickHouse/ClickHouse/pull/81823) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Header Connection is send at the end of headers. When we know is the connection should be preserved. [#81951](https://github.com/ClickHouse/ClickHouse/pull/81951) ([Sema Checherinda](https://github.com/CheSema)).
* Tune TCP servers queue (64 by default) based on listen\_backlog (4096 by default). [#82045](https://github.com/ClickHouse/ClickHouse/pull/82045) ([Azat Khuzhin](https://github.com/azat)).
* Add ability to reload `max_local_read_bandwidth_for_server` and `max_local_write_bandwidth_for_server` on fly without restart server. [#82083](https://github.com/ClickHouse/ClickHouse/pull/82083) ([Kai Zhu](https://github.com/nauu)).
* Add support for clearing all warnings from the `system.warnings` table using `TRUNCATE TABLE system.warnings`. [#82087](https://github.com/ClickHouse/ClickHouse/pull/82087) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix partition pruning with data lake cluster functions. [#82131](https://github.com/ClickHouse/ClickHouse/pull/82131) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix reading partitioned data in DeltaLakeCluster table function. In this PR cluster functions protocol version is increased, allowing to send extra info from initiator to replicas. This extra info contains delta-kernel transform expression, which is needed to parse partition columns (and some other staff in the future, like generated columns, etc). [#82132](https://github.com/ClickHouse/ClickHouse/pull/82132) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Function `reinterpret` function now supports conversion to `Array(T)` where `T` is a fixed-size data type (issue [#82621](https://github.com/ClickHouse/ClickHouse/issues/82621)). [#83399](https://github.com/ClickHouse/ClickHouse/pull/83399) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Now database Datalake throw more convenient exception. Fixes [#81211](https://github.com/ClickHouse/ClickHouse/issues/81211). [#82304](https://github.com/ClickHouse/ClickHouse/pull/82304) ([alesapin](https://github.com/alesapin)).
* Improve CROSS JOIN by returning false from `HashJoin::needUsedFlagsForPerRightTableRow`. [#82379](https://github.com/ClickHouse/ClickHouse/pull/82379) ([lgbo](https://github.com/lgbo-ustc)).
* Allow write/read map columns as Array of Tuples. [#82408](https://github.com/ClickHouse/ClickHouse/pull/82408) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* List the licenses of [Rust](https://clickhouse.com/blog/rust) crates in `system.licenses`. [#82440](https://github.com/ClickHouse/ClickHouse/pull/82440) ([Raúl Marín](https://github.com/Algunenano)).
* Macros like `{uuid}` can now be used in the `keeper_path` setting of the S3Queue table engine. [#82463](https://github.com/ClickHouse/ClickHouse/pull/82463) ([Nikolay Degterinsky](https://github.com/evillique)).
* Keeper improvement: move changelog files between disk in a background thread. Previously, moving changelog to a different disk would block Keeper globally until the move is finished. This lead to performance degradation if moving is a long operation (e.g. to S3 disk). [#82485](https://github.com/ClickHouse/ClickHouse/pull/82485) ([Antonio Andelic](https://github.com/antonio2368)).
* Keeper improvement: add new config `keeper_server.cleanup_old_and_ignore_new_acl`. If enabled, all nodes will have their ACLs cleared while ACL for new requests will be ignored. If the goal is to completely remove ACL from nodes, it's important to leave the config enabled until a new snapshot is created. [#82496](https://github.com/ClickHouse/ClickHouse/pull/82496) ([Antonio Andelic](https://github.com/antonio2368)).
* Added a new server setting `s3queue_disable_streaming` which disables streaming in tables with S3Queue table engine. This setting is changeable without server restart. [#82515](https://github.com/ClickHouse/ClickHouse/pull/82515) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Refactor dynamic resize feature of filesystem cache. Added more logs for introspection. [#82556](https://github.com/ClickHouse/ClickHouse/pull/82556) ([Kseniia Sumarokova](https://github.com/kssenii)).
* `clickhouse-server` without a configuration file will also listen to the PostgreSQL port 9005, like with the default config. [#82633](https://github.com/ClickHouse/ClickHouse/pull/82633) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* In `ReplicatedMergeTree::executeMetadataAlter`, we get the StorageID, and without taking DDLGuard, we try to call `IDatabase::alterTable`. In between this time we could have technically exchanged the table in question with another table, so when we get the definiton we would get the wrong one. To avoid this we add a separate check for UUIDs to match when we try to call `IDatabase::alterTable`. [#82666](https://github.com/ClickHouse/ClickHouse/pull/82666) ([Nikolay Degterinsky](https://github.com/evillique)).
* When attaching a database with a read-only remote disk, manually add table UUIDs into DatabaseCatalog. [#82670](https://github.com/ClickHouse/ClickHouse/pull/82670) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Prevent user from using `nan` and `inf` with `NumericIndexedVector`. Fixes [#82239](https://github.com/ClickHouse/ClickHouse/issues/82239) and a little more. [#82681](https://github.com/ClickHouse/ClickHouse/pull/82681) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Do not omit zero values in the `X-ClickHouse-Progress` and `X-ClickHouse-Summary` header formats. [#82727](https://github.com/ClickHouse/ClickHouse/pull/82727) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Keeper improvement: support specific permissions for world:anyone ACL. [#82755](https://github.com/ClickHouse/ClickHouse/pull/82755) ([Antonio Andelic](https://github.com/antonio2368)).
* Do not allow `RENAME COLUMN` or `DROP COLUMN` involving explicitly listed columns to sum in SummingMergeTree. Closes [#81836](https://github.com/ClickHouse/ClickHouse/issues/81836). [#82821](https://github.com/ClickHouse/ClickHouse/pull/82821) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Improve the precision of conversion from `Decimal` to `Float32`. Implement conversion from `Decimal` to `BFloat16`. Closes [#82660](https://github.com/ClickHouse/ClickHouse/issues/82660). [#82823](https://github.com/ClickHouse/ClickHouse/pull/82823) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Scrollbars in the Web UI will look slightly better. [#82869](https://github.com/ClickHouse/ClickHouse/pull/82869) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* `clickhouse-server` with embedded configuration will allow using the Web UI by providing an HTTP OPTIONS response. [#82870](https://github.com/ClickHouse/ClickHouse/pull/82870) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add support for specifying extra Keeper ACL for paths in config. If you want to add extra ACL for a specific path you define it in the config under `zookeeper.path_acls`. [#82898](https://github.com/ClickHouse/ClickHouse/pull/82898) ([Antonio Andelic](https://github.com/antonio2368)).
* Now mutations snapshot will be built from the visible parts snapshot. Also mutation counters used in snapshot will be recalculated from the included mutations. [#82945](https://github.com/ClickHouse/ClickHouse/pull/82945) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Adds ProfileEvent when Keeper rejects a write due to soft memory limit. [#82963](https://github.com/ClickHouse/ClickHouse/pull/82963) ([Xander Garbett](https://github.com/Garbett1)).
* Add columns `commit_time`, `commit_id` to `system.s3queue_log`. [#83016](https://github.com/ClickHouse/ClickHouse/pull/83016) ([Kseniia Sumarokova](https://github.com/kssenii)).
* In some cases, we need to have multiple dimensions to our metrics. For example, counting failed merges or mutations by error codes rather than having a single counter. Introduce `system.dimensional_metrics`, which does precisely that and adds the first dimensional metric called `failed_merges`. [#83030](https://github.com/ClickHouse/ClickHouse/pull/83030) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Consolidate unknown settings warnings in clickhouse client and log them as a summary. [#83042](https://github.com/ClickHouse/ClickHouse/pull/83042) ([Bharat Nallan](https://github.com/bharatnc)).
* Clickhouse client now reports the local port when connection error happens. [#83050](https://github.com/ClickHouse/ClickHouse/pull/83050) ([Jianfei Hu](https://github.com/incfly)).
* Slightly better error handling in `AsynchronousMetrics`. If the `/sys/block` directory exists but is not accessible, the server will start without monitoring the block devices. Closes [#79229](https://github.com/ClickHouse/ClickHouse/issues/79229). [#83115](https://github.com/ClickHouse/ClickHouse/pull/83115) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Shutdown SystemLogs after ordinary tables (and before system tables, instead of before ordinary). [#83134](https://github.com/ClickHouse/ClickHouse/pull/83134) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Add logs for `S3Queue` shutdown process. [#83163](https://github.com/ClickHouse/ClickHouse/pull/83163) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Possibility to parse `Time` and `Time64` as `MM:SS`, `M:SS`, `SS`, or `S`. [#83299](https://github.com/ClickHouse/ClickHouse/pull/83299) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* When `distributed_ddl_output_mode='*_only_active'`, don't wait for new or recovered replicas that have replication lag bigger than `max_replication_lag_to_enqueue`. This should help to avoid `DDL task is not finished on some hosts` when a new replica becomes active after finishing initialization or recovery, but it accumulated huge replication log while initializing. Also, implement `SYSTEM SYNC DATABASE REPLICA STRICT` query that waits for replication log to become below `max_replication_lag_to_enqueue`. [#83302](https://github.com/ClickHouse/ClickHouse/pull/83302) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Do not output too long descriptions of expression actions in exception messages. Closes [#83164](https://github.com/ClickHouse/ClickHouse/issues/83164). [#83350](https://github.com/ClickHouse/ClickHouse/pull/83350) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add ability to parse part's prefix and suffix and also check coverage for non constant columns. [#83377](https://github.com/ClickHouse/ClickHouse/pull/83377) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Unify parameter names in ODBC and JDBC when using named collections. [#83410](https://github.com/ClickHouse/ClickHouse/pull/83410) ([Andrey Zvonov](https://github.com/zvonand)).
* When the storage is shutting down, `getStatus` throws an `ErrorCodes::ABORTED` exception. Previously, this would fail the select query. Now we catch the `ErrorCodes::ABORTED` exceptions and intentionally ignore them instead. [#83435](https://github.com/ClickHouse/ClickHouse/pull/83435) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Add process resource metrics (such as `UserTimeMicroseconds`, `SystemTimeMicroseconds`, `RealTimeMicroseconds`) to part\_log profile events for `MergeParts` entries. [#83460](https://github.com/ClickHouse/ClickHouse/pull/83460) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Enable `create_if_not_exists`, `check_not_exists`, `remove_recursive` feature flags in Keeper by default which enable new types of requests. [#83488](https://github.com/ClickHouse/ClickHouse/pull/83488) ([Antonio Andelic](https://github.com/antonio2368)).
* Shutdown S3(Azure/etc)Queue streaming before shutting down any tables on server shutdown. [#83530](https://github.com/ClickHouse/ClickHouse/pull/83530) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Enable `Date`/`Date32` as integers in `JSON` input formats. [#83597](https://github.com/ClickHouse/ClickHouse/pull/83597) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* Made exception messages for certain situations for loading and adding projections easier to read. [#83728](https://github.com/ClickHouse/ClickHouse/pull/83728) ([Robert Schulze](https://github.com/rschu1ze)).
* Introduce a configuration option to skip binary checksum integrity checks for `clickhouse-server`. Resolves [#83637](https://github.com/ClickHouse/ClickHouse/issues/83637). [#83749](https://github.com/ClickHouse/ClickHouse/pull/83749) ([Rafael Roquetto](https://github.com/rafaelroquetto)).
#### Bug Fix (user-visible misbehavior in an official stable release)
* Fix the wrong default value for the `--reconnect` option in `clickhouse-benchmark`. It was changed by mistake in [#79465](https://github.com/ClickHouse/ClickHouse/issues/79465). [#82677](https://github.com/ClickHouse/ClickHouse/pull/82677) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix inconsistent formatting of `CREATE DICTIONARY`. Closes [#82105](https://github.com/ClickHouse/ClickHouse/issues/82105). [#82829](https://github.com/ClickHouse/ClickHouse/pull/82829) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix inconsistent formatting of TTL when it contains a `materialize` function. Closes [#82828](https://github.com/ClickHouse/ClickHouse/issues/82828). [#82831](https://github.com/ClickHouse/ClickHouse/pull/82831) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix inconsistent formatting of EXPLAIN AST in a subquery when it contains output options such as INTO OUTFILE. Closes [#82826](https://github.com/ClickHouse/ClickHouse/issues/82826). [#82840](https://github.com/ClickHouse/ClickHouse/pull/82840) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix inconsistent formatting of parenthesized expressions with aliases in the context when no aliases are allowed. Closes [#82836](https://github.com/ClickHouse/ClickHouse/issues/82836). Closes [#82837](https://github.com/ClickHouse/ClickHouse/issues/82837). [#82867](https://github.com/ClickHouse/ClickHouse/pull/82867) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Use the proper error code when multiplying an aggregate function state with IPv4. Closes [#82817](https://github.com/ClickHouse/ClickHouse/issues/82817). [#82818](https://github.com/ClickHouse/ClickHouse/pull/82818) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix logical error in filesystem cache: "Having zero bytes but range is not finished". [#81868](https://github.com/ClickHouse/ClickHouse/pull/81868) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Recalculate the min-max index when TTL reduces rows to ensure the correctness of algorithms relying on it, such as `minmax_count_projection`. This resolves [#77091](https://github.com/ClickHouse/ClickHouse/issues/77091). [#77166](https://github.com/ClickHouse/ClickHouse/pull/77166) ([Amos Bird](https://github.com/amosbird)).
* For queries with combination of `ORDER BY ... LIMIT BY ... LIMIT N`, when ORDER BY is executed as a PartialSorting, the counter `rows_before_limit_at_least` now reflects the number of rows consumed by LIMIT clause instead of number of rows consumed by sorting transform. [#78999](https://github.com/ClickHouse/ClickHouse/pull/78999) ([Eduard Karacharov](https://github.com/korowa)).
* Fix excessive granule skipping for filtering over token/ngram indexes with regexp which contains alternation and non-literal first alternative. [#79373](https://github.com/ClickHouse/ClickHouse/pull/79373) ([Eduard Karacharov](https://github.com/korowa)).
* Fix logical error with `<=>` operator and Join storage, now query returns proper error code. [#80165](https://github.com/ClickHouse/ClickHouse/pull/80165) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix a crash in the `loop` function when used with the `remote` function family. Ensure the LIMIT clause is respected in `loop(remote(...))`. [#80299](https://github.com/ClickHouse/ClickHouse/pull/80299) ([Julia Kartseva](https://github.com/jkartseva)).
* Fix incorrect behavior of `to_utc_timestamp` and `from_utc_timestamp` functions when handling dates before Unix epoch (1970-01-01) and after maximum date (2106-02-07 06:28:15). Now these functions properly clamp values to epoch start and maximum date respectively. [#80498](https://github.com/ClickHouse/ClickHouse/pull/80498) ([Surya Kant Ranjan](https://github.com/iit2009046)).
* For some queries executed with parallel replicas, reading in order optimization(s) could be applied on initiator while can't be applied on remote nodes. It leads to different reading modes used by parallel replicas coordinator (on initiator) and on remoted nodes, which is a logical error. [#80652](https://github.com/ClickHouse/ClickHouse/pull/80652) ([Igor Nikonov](https://github.com/devcrafter)).
* Fix logical error during materialize projection when column type was changed to Nullable. [#80741](https://github.com/ClickHouse/ClickHouse/pull/80741) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix incorrect TTL recalculation in TTL GROUP BY when updating TTL. [#81222](https://github.com/ClickHouse/ClickHouse/pull/81222) ([Evgeniy Ulasik](https://github.com/H0uston)).
* Fixed Parquet bloom filter incorrectly applying condition like `WHERE function(key) IN (...)` as if it were `WHERE key IN (...)`. [#81255](https://github.com/ClickHouse/ClickHouse/pull/81255) ([Michael Kolupaev](https://github.com/al13n321)).
* Fixed possible crash in `Aggregator` in case of exception during merge. [#81450](https://github.com/ClickHouse/ClickHouse/pull/81450) ([Nikita Taranov](https://github.com/nickitat)).
* Fixed `InterpreterInsertQuery::extendQueryLogElemImpl` to add backquotes to database and table names when needed (f.g., when names contain special characters like `-`). [#81528](https://github.com/ClickHouse/ClickHouse/pull/81528) ([Ilia Shvyrialkin](https://github.com/Harzu)).
* Fix `IN` execution with `transform_null_in=1` with null in the left argument and non-nullable subquery result. [#81584](https://github.com/ClickHouse/ClickHouse/pull/81584) ([Pavel Kruglov](https://github.com/Avogar)).
* Don't validate experimental/suspicious types in default/materialize expression execution during reading from existing table. [#81618](https://github.com/ClickHouse/ClickHouse/pull/81618) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix "Context has expired" during merges when dict used in TTL expression. [#81690](https://github.com/ClickHouse/ClickHouse/pull/81690) ([Azat Khuzhin](https://github.com/azat)).
* Fix monotonicity of the cast function. [#81722](https://github.com/ClickHouse/ClickHouse/pull/81722) ([zoomxi](https://github.com/zoomxi)).
* Fix the issue where required columns are not read during scalar correlated subquery processing. Fixes [#81716](https://github.com/ClickHouse/ClickHouse/issues/81716). [#81805](https://github.com/ClickHouse/ClickHouse/pull/81805) ([Dmitry Novik](https://github.com/novikd)).
* In previous versions, the server returned excessive content for requests to `/js`. This closes [#61890](https://github.com/ClickHouse/ClickHouse/issues/61890). [#81895](https://github.com/ClickHouse/ClickHouse/pull/81895) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Previously, `MongoDB` table engine definitions could include a path component in the `host:port` argument which was silently ignored. The mongodb integration refuses to load such tables. With this fix *we allow loading such tables and ignore path component* if `MongoDB` engine has five arguments, using the database name from arguments. *Note:* The fix is not applied for newly created tables or queries with `mongo` table function, as well as for dictionary sources and named collections. [#81942](https://github.com/ClickHouse/ClickHouse/pull/81942) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fixed possible crash in `Aggregator` in case of exception during merge. [#82022](https://github.com/ClickHouse/ClickHouse/pull/82022) ([Nikita Taranov](https://github.com/nickitat)).
* Fix filter analysis when only a constant alias column is used in the query. Fixes [#79448](https://github.com/ClickHouse/ClickHouse/issues/79448). [#82037](https://github.com/ClickHouse/ClickHouse/pull/82037) ([Dmitry Novik](https://github.com/novikd)).
* Fix LOGICAL\_ERROR and following crash when using the same column in the TTL for GROUP BY and SET. [#82054](https://github.com/ClickHouse/ClickHouse/pull/82054) ([Pablo Marcos](https://github.com/pamarcos)).
* Fix S3 table function argument validation in secret masking, preventing possible `LOGICAL_ERROR`, close [#80620](https://github.com/ClickHouse/ClickHouse/issues/80620). [#82056](https://github.com/ClickHouse/ClickHouse/pull/82056) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix data races in Iceberg. [#82088](https://github.com/ClickHouse/ClickHouse/pull/82088) ([Azat Khuzhin](https://github.com/azat)).
* Fix `DatabaseReplicated::getClusterImpl`. If the first element (or elements) of `hosts` has `id == DROPPED_MARK` and there are no other elements for the same shard, the first element of `shards` will be an empty vector, leading to `std::out_of_range`. [#82093](https://github.com/ClickHouse/ClickHouse/pull/82093) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Fixing copy-paste error in arraySimilarity, disallowing the use of UInt32 and Int32 weights. Update tests and docs. [#82103](https://github.com/ClickHouse/ClickHouse/pull/82103) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
* Fix the `Not found column` error for queries with `arrayJoin` under `WHERE` condition and `IndexSet`. [#82113](https://github.com/ClickHouse/ClickHouse/pull/82113) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fix bug in glue catalog integration. Now clickhouse can read tables with nested data types where some of subcolumns contain decimals, for example: `map`. Fixes [#81301](https://github.com/ClickHouse/ClickHouse/issues/81301). [#82114](https://github.com/ClickHouse/ClickHouse/pull/82114) ([alesapin](https://github.com/alesapin)).
* Fix performance degradation in SummingMergeTree that was intorduced in 25.5 in [https://github.com/ClickHouse/ClickHouse/pull/79051](https://github.com/ClickHouse/ClickHouse/pull/79051). [#82130](https://github.com/ClickHouse/ClickHouse/pull/82130) ([Pavel Kruglov](https://github.com/Avogar)).
* When passing settings over uri the last value is considered. [#82137](https://github.com/ClickHouse/ClickHouse/pull/82137) ([Sema Checherinda](https://github.com/CheSema)).
* Fix "Context has expired" for Iceberg. [#82146](https://github.com/ClickHouse/ClickHouse/pull/82146) ([Azat Khuzhin](https://github.com/azat)).
* Fix possible deadlock for remote queries when server is under memory pressure. [#82160](https://github.com/ClickHouse/ClickHouse/pull/82160) ([Kirill](https://github.com/kirillgarbar)).
* Fixes overflow in `numericIndexedVectorPointwiseAdd`, `numericIndexedVectorPointwiseSubtract`, `numericIndexedVectorPointwiseMultiply`, `numericIndexedVectorPointwiseDivide` functions that happened when we applied them to large numbers. [#82165](https://github.com/ClickHouse/ClickHouse/pull/82165) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Fix a bug in table dependencies causing Materialized Views to miss INSERT queries. [#82222](https://github.com/ClickHouse/ClickHouse/pull/82222) ([Nikolay Degterinsky](https://github.com/evillique)).
* Fix possible data-race between suggestion thread and main client thread. [#82233](https://github.com/ClickHouse/ClickHouse/pull/82233) ([Azat Khuzhin](https://github.com/azat)).
* Now ClickHouse can read iceberg tables from Glue catalog after schema evolution. Fixes [#81272](https://github.com/ClickHouse/ClickHouse/issues/81272). [#82301](https://github.com/ClickHouse/ClickHouse/pull/82301) ([alesapin](https://github.com/alesapin)).
* Fix the validation of async metrics settings `asynchronous_metrics_update_period_s` and `asynchronous_heavy_metrics_update_period_s`. [#82310](https://github.com/ClickHouse/ClickHouse/pull/82310) ([Bharat Nallan](https://github.com/bharatnc)).
* Fix logical error when resolving matcher in query with multiple JOINs, close [#81969](https://github.com/ClickHouse/ClickHouse/issues/81969). [#82421](https://github.com/ClickHouse/ClickHouse/pull/82421) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Add expiration to AWS ECS token so it can be reloaded. [#82422](https://github.com/ClickHouse/ClickHouse/pull/82422) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fixes a bug for `NULL` arguments in `CASE` function. [#82436](https://github.com/ClickHouse/ClickHouse/pull/82436) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Fix data-races in client (by not using global context) and `session_timezone` overrides (previously in case of `session_timezone` was set in i.e. `users.xml`/client options to non empty and in query context to empty, then, value from `users.xml` was used, while this is wrong, now query context will always have a priority over global context). [#82444](https://github.com/ClickHouse/ClickHouse/pull/82444) ([Azat Khuzhin](https://github.com/azat)).
* Fix disabling boundary alignment for cached buffer in external table engines. It was broken in [https://github.com/ClickHouse/ClickHouse/pull/81868](https://github.com/ClickHouse/ClickHouse/pull/81868). [#82493](https://github.com/ClickHouse/ClickHouse/pull/82493) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix the crash if key-value storage is joined with a type-casted key. [#82497](https://github.com/ClickHouse/ClickHouse/pull/82497) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Fix hiding named collection values in logs/query\_log. Closes [#82405](https://github.com/ClickHouse/ClickHouse/issues/82405). [#82510](https://github.com/ClickHouse/ClickHouse/pull/82510) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix a possible crash in logging while terminating a session as the user\_id might sometimes be empty. [#82513](https://github.com/ClickHouse/ClickHouse/pull/82513) ([Bharat Nallan](https://github.com/bharatnc)).
* Fixes cases where parsing of Time could cause msan issues. This fixes: [#82477](https://github.com/ClickHouse/ClickHouse/issues/82477). [#82514](https://github.com/ClickHouse/ClickHouse/pull/82514) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Disallow setting `threadpool_writer_pool_size` to zero to ensure that server operations don't get stuck. [#82532](https://github.com/ClickHouse/ClickHouse/pull/82532) ([Bharat Nallan](https://github.com/bharatnc)).
* Fix `LOGICAL_ERROR` during row policy expression analysis for correlated columns. [#82618](https://github.com/ClickHouse/ClickHouse/pull/82618) ([Dmitry Novik](https://github.com/novikd)).
* Fix incorrect usage of parent metadata in `mergeTreeProjection` table function when `enable_shared_storage_snapshot_in_query = 1`. This is for [#82634](https://github.com/ClickHouse/ClickHouse/issues/82634). [#82638](https://github.com/ClickHouse/ClickHouse/pull/82638) ([Amos Bird](https://github.com/amosbird)).
* Functions `trim{Left,Right,Both}` now support input strings of type "FixedString(N)". For example, `SELECT trimBoth(toFixedString('abc', 3), 'ac')` now works. [#82691](https://github.com/ClickHouse/ClickHouse/pull/82691) ([Robert Schulze](https://github.com/rschu1ze)).
* In AzureBlobStorage, for native copy we compare authentication methods, during which if we get an exception, updated the code to fallback to read and copy (i.e. non native copy). [#82693](https://github.com/ClickHouse/ClickHouse/pull/82693) ([Smita Kulkarni](https://github.com/SmitaRKulkarni)).
* Fix deserialization of `groupArraySample`/`groupArrayLast` in case of empty elements (deserialization could skip part of the binary if the input was empty, this can lead to corruption during data read and UNKNOWN\_PACKET\_FROM\_SERVER in TCP protocol). This does not affect numbers and date time types. [#82763](https://github.com/ClickHouse/ClickHouse/pull/82763) ([Pedro Ferreira](https://github.com/PedroTadim)).
* Fix backup of an empty `Memory` table, causing the backup restore to fail with with `BACKUP_ENTRY_NOT_FOUND` error. [#82791](https://github.com/ClickHouse/ClickHouse/pull/82791) ([Julia Kartseva](https://github.com/jkartseva)).
* Fix exception safety in union/intersect/except\_default\_mode rewrite. Closes [#82664](https://github.com/ClickHouse/ClickHouse/issues/82664). [#82820](https://github.com/ClickHouse/ClickHouse/pull/82820) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Keep track of the number of async tables loading jobs. If there are some running jobs, do not update `tail_ptr` in `TransactionLog::removeOldEntries`. [#82824](https://github.com/ClickHouse/ClickHouse/pull/82824) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Fix data races in Iceberg. [#82841](https://github.com/ClickHouse/ClickHouse/pull/82841) ([Azat Khuzhin](https://github.com/azat)).
* Setting `use_skip_indexes_if_final_exact_mode` optimization (introduced in 25.6) could fail to select a relevant candidate range depending upon `MergeTree` engine settings / data distribution. That has been resolved now. [#82879](https://github.com/ClickHouse/ClickHouse/pull/82879) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Set salt for auth data when parsing from AST with type SCRAM\_SHA256\_PASSWORD. [#82888](https://github.com/ClickHouse/ClickHouse/pull/82888) ([Tuan Pham Anh](https://github.com/tuanpach)).
* When using a non-caching Database implementation, the metadata of the corresponding table is deleted after the columns are returned and the reference is invalidated. [#82939](https://github.com/ClickHouse/ClickHouse/pull/82939) ([buyval01](https://github.com/buyval01)).
* Fix filter modification for queries with a JOIN expression with a table with storage `Merge`. Fixes [#82092](https://github.com/ClickHouse/ClickHouse/issues/82092). [#82950](https://github.com/ClickHouse/ClickHouse/pull/82950) ([Dmitry Novik](https://github.com/novikd)).
* Fix LOGICAL\_ERROR in QueryMetricLog: Mutex cannot be NULL. [#82979](https://github.com/ClickHouse/ClickHouse/pull/82979) ([Pablo Marcos](https://github.com/pamarcos)).
* Fixed incorrect output of function `formatDateTime` when formatter `%f` is used together with variable-size formatters (e.g. `%M`). [#83020](https://github.com/ClickHouse/ClickHouse/pull/83020) ([Robert Schulze](https://github.com/rschu1ze)).
* Fix performance degradation with the enabled analyzer when secondary queries always read all columns from the VIEWs. Fixes [#81718](https://github.com/ClickHouse/ClickHouse/issues/81718). [#83036](https://github.com/ClickHouse/ClickHouse/pull/83036) ([Dmitry Novik](https://github.com/novikd)).
* Fix misleading error message when restoring a backup on a read-only disk. [#83051](https://github.com/ClickHouse/ClickHouse/pull/83051) ([Julia Kartseva](https://github.com/jkartseva)).
* Do not check for cyclic dependencies on create table with no dependencies. It fixes performance degradation of the use cases with creation of thousands of tables that was introduced in [https://github.com/ClickHouse/ClickHouse/pull/65405](https://github.com/ClickHouse/ClickHouse/pull/65405). [#83077](https://github.com/ClickHouse/ClickHouse/pull/83077) ([Pavel Kruglov](https://github.com/Avogar)).
* Fixes issue with implicit reading of negative Time values into the table and make the docs not confusing. [#83091](https://github.com/ClickHouse/ClickHouse/pull/83091) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Do not use unrelated parts of a shared dictionary in the `lowCardinalityKeys` function. [#83118](https://github.com/ClickHouse/ClickHouse/pull/83118) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix the regression in use of subcolumns with Materialized Views. This fixes: [#82784](https://github.com/ClickHouse/ClickHouse/issues/82784). [#83221](https://github.com/ClickHouse/ClickHouse/pull/83221) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Fix crash in client due to connection left in disconnected state after bad INSERT. [#83253](https://github.com/ClickHouse/ClickHouse/pull/83253) ([Azat Khuzhin](https://github.com/azat)).
* Fix crash when calculating the size of a block with empty columns. [#83271](https://github.com/ClickHouse/ClickHouse/pull/83271) ([Raúl Marín](https://github.com/Algunenano)).
* Fix possible crash in Variant type in UNION. [#83295](https://github.com/ClickHouse/ClickHouse/pull/83295) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix LOGICAL\_ERROR in clickhouse-local for unsupported SYSTEM queries. [#83333](https://github.com/ClickHouse/ClickHouse/pull/83333) ([Surya Kant Ranjan](https://github.com/iit2009046)).
* Fix `no_sign_request` for S3 client. It can be used to explicitly avoid signing S3 requests. It can also be defined for specific endpoints using endpoint-based settings. [#83379](https://github.com/ClickHouse/ClickHouse/pull/83379) ([Antonio Andelic](https://github.com/antonio2368)).
* Fixes a crash that may happen for a query with a setting 'max\_threads=1' when executed under load with CPU scheduling enabled. [#83387](https://github.com/ClickHouse/ClickHouse/pull/83387) ([Fan Ziqi](https://github.com/f2quantum)).
* Fix `TOO_DEEP_SUBQUERIES` exception when CTE definition references another table expression with the same name. [#83413](https://github.com/ClickHouse/ClickHouse/pull/83413) ([Dmitry Novik](https://github.com/novikd)).
* Fix incorrect behavior when executing `REVOKE S3 ON system.*` revokes S3 permissions for `*.*`. This fixes [#83417](https://github.com/ClickHouse/ClickHouse/issues/83417). [#83420](https://github.com/ClickHouse/ClickHouse/pull/83420) ([pufit](https://github.com/pufit)).
* Do not share async\_read\_counters between queries. [#83423](https://github.com/ClickHouse/ClickHouse/pull/83423) ([Azat Khuzhin](https://github.com/azat)).
* Disable parallel replicas when a subquery contains the FINAL. [#83455](https://github.com/ClickHouse/ClickHouse/pull/83455) ([zoomxi](https://github.com/zoomxi)).
* Resolve minor integer overflow in configuration of setting `role_cache_expiration_time_seconds` (issue [#83374](https://github.com/ClickHouse/ClickHouse/issues/83374)). [#83461](https://github.com/ClickHouse/ClickHouse/pull/83461) ([wushap](https://github.com/wushap)).
* Fix a bug introduced in [https://github.com/ClickHouse/ClickHouse/pull/79963](https://github.com/ClickHouse/ClickHouse/pull/79963). When inserting into an MV with a definer, the permission check should use the definer's grants. This fixes [#79951](https://github.com/ClickHouse/ClickHouse/issues/79951). [#83502](https://github.com/ClickHouse/ClickHouse/pull/83502) ([pufit](https://github.com/pufit)).
* Disable bounds-based file pruning for iceberg array element and iceberg map values, including all their nested subfields. [#83520](https://github.com/ClickHouse/ClickHouse/pull/83520) ([Daniil Ivanik](https://github.com/divanik)).
* Fix possible file cache not initialized errors when it's used as a temporary data storage. [#83539](https://github.com/ClickHouse/ClickHouse/pull/83539) ([Bharat Nallan](https://github.com/bharatnc)).
* Keeper fix: update total watch count correctly when ephemeral nodes are deleted on session close. [#83583](https://github.com/ClickHouse/ClickHouse/pull/83583) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix incorrect memory around max\_untracked\_memory. [#83607](https://github.com/ClickHouse/ClickHouse/pull/83607) ([Azat Khuzhin](https://github.com/azat)).
* INSERT SELECT with UNION ALL could lead to a null pointer dereference in a corner case. This closes [#83618](https://github.com/ClickHouse/ClickHouse/issues/83618). [#83643](https://github.com/ClickHouse/ClickHouse/pull/83643) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Disallow zero value for max\_insert\_block\_size as it could cause logical error. [#83688](https://github.com/ClickHouse/ClickHouse/pull/83688) ([Bharat Nallan](https://github.com/bharatnc)).
* Fix endless loop in estimateCompressionRatio() with block\_size\_bytes=0. [#83704](https://github.com/ClickHouse/ClickHouse/pull/83704) ([Azat Khuzhin](https://github.com/azat)).
* Fix `IndexUncompressedCacheBytes`/`IndexUncompressedCacheCells`/`IndexMarkCacheBytes`/`IndexMarkCacheFiles` metrics (previously they were included into metric w/o `Cache` prefix). [#83730](https://github.com/ClickHouse/ClickHouse/pull/83730) ([Azat Khuzhin](https://github.com/azat)).
* Fix possible abort (due to joining threads from the task) and hopefully hungs (in unit tests) during `BackgroundSchedulePool` shutdown. [#83769](https://github.com/ClickHouse/ClickHouse/pull/83769) ([Azat Khuzhin](https://github.com/azat)).
* Introduce backward compatibility setting to allow new analyzer to reference outer alias in WITH clause in the case of name clashes. Fixes [#82700](https://github.com/ClickHouse/ClickHouse/issues/82700). [#83797](https://github.com/ClickHouse/ClickHouse/pull/83797) ([Dmitry Novik](https://github.com/novikd)).
* Fix deadlock on shutdown due to recursive context locking during library bridge cleanup. [#83824](https://github.com/ClickHouse/ClickHouse/pull/83824) ([Azat Khuzhin](https://github.com/azat)).
#### Build/Testing/Packaging Improvement
* Build a minimal C library (10 KB) for the ClickHouse lexer. This is needed for [#80977](https://github.com/ClickHouse/ClickHouse/issues/80977). [#81347](https://github.com/ClickHouse/ClickHouse/pull/81347) ([Alexey Milovidov](https://github.com/alexey-milovidov)). Add test for standalone lexer, add test tag `fasttest-only`. [#82472](https://github.com/ClickHouse/ClickHouse/pull/82472) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Add a check for Nix submodule inputs. [#81691](https://github.com/ClickHouse/ClickHouse/pull/81691) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fix a list of problems that can occur when trying to run integration tests on a localhost. [#82135](https://github.com/ClickHouse/ClickHouse/pull/82135) ([Oleg Doronin](https://github.com/dorooleg)).
* Compile SymbolIndex on Mac and FreeBSD. (But it will work only on ELF systems, Linux and FreeBSD). [#82347](https://github.com/ClickHouse/ClickHouse/pull/82347) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Bumped Azure SDK to v1.15.0. [#82747](https://github.com/ClickHouse/ClickHouse/pull/82747) ([Smita Kulkarni](https://github.com/SmitaRKulkarni)).
* Add storage module from google-cloud-cpp to build system. [#82881](https://github.com/ClickHouse/ClickHouse/pull/82881) ([Pablo Marcos](https://github.com/pamarcos)).
* Change `Dockerfile.ubuntu` for clickhouse-server to fit requirements in Docker Official Library. [#83039](https://github.com/ClickHouse/ClickHouse/pull/83039) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
* A follow-up for [#83158](https://github.com/ClickHouse/ClickHouse/issues/83158) to fix uploading builds to `curl clickhouse.com`. [#83463](https://github.com/ClickHouse/ClickHouse/pull/83463) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
* Adding `busybox` binary and install tools in `clickhouse/clickhouse-server` and official `clickhouse` images. [#83735](https://github.com/ClickHouse/ClickHouse/pull/83735) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
* Added support for the `CLICKHOUSE_HOST` environment variable to specify the ClickHouse server host, aligning with existing `CLICKHOUSE_USER` and `CLICKHOUSE_PASSWORD` environment variables. This allows for easier configuration without modifying client or configuration files directly. [#83659](https://github.com/ClickHouse/ClickHouse/pull/83659) ([Doron David](https://github.com/dorki)).
ClickHouse release 25.6, 2025-06-26
#### Backward Incompatible Change
* Previously, function `countMatches` would stop counting at the first empty match even if the pattern accepts it. To overcome this issue, `countMatches` now continues execution by advancing by a single character when an empty match occurs. Users who like to retain the old behavior can enable setting `count_matches_stop_at_empty_match`. [#81676](https://github.com/ClickHouse/ClickHouse/pull/81676) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Minor: Force `backup_threads` and `restore_threads` server settings to be non zero. [#80224](https://github.com/ClickHouse/ClickHouse/pull/80224) ([Raúl Marín](https://github.com/Algunenano)).
* Minor: Fix `bitNot` for `String` will return a zero-terminated string in the internal memory representation. This should not affect any user visible behavior, however the author wanted to highlight this change. [#80791](https://github.com/ClickHouse/ClickHouse/pull/80791) ([Azat Khuzhin](https://github.com/azat)).
#### New Feature
* New data types: `Time` (\[H]HH:MM:SS) and `Time64` (\[H]HH:MM:SS\[.fractional]), and some basic cast functions and functions to interact with other data types. Added settings for compatibility with the existing function `toTime`. The setting `use_legacy_to_time` is set to keep the old behavior for now. [#81217](https://github.com/ClickHouse/ClickHouse/pull/81217) ([Yarik Briukhovetskyi](https://github.com/yariks5s)). Support comparison between Time/Time64. [#80327](https://github.com/ClickHouse/ClickHouse/pull/80327) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* A new CLI tool, [`chdig`](https://github.com/azat/chdig/) - TUI interface for ClickHouse (top like) as part of ClickHouse. [#79666](https://github.com/ClickHouse/ClickHouse/pull/79666) ([Azat Khuzhin](https://github.com/azat)).
* Support `disk` setting for `Atomic` and `Ordinary` database engines, specifying the disk to store table metadata files. [#80546](https://github.com/ClickHouse/ClickHouse/pull/80546) ([Tuan Pham Anh](https://github.com/tuanpach)). This allows attaching databases from external sources.
* A new type of MergeTree, `CoalescingMergeTree` - the engine takes the first non-Null value during background merges. This closes [#78869](https://github.com/ClickHouse/ClickHouse/issues/78869). [#79344](https://github.com/ClickHouse/ClickHouse/pull/79344) ([scanhex12](https://github.com/scanhex12)).
* Support functions to read WKB ("Well-Known Binary" is a format for binary encoding of various geometry types, used in GIS applications). See [#43941](https://github.com/ClickHouse/ClickHouse/issues/43941). [#80139](https://github.com/ClickHouse/ClickHouse/pull/80139) ([scanhex12](https://github.com/scanhex12)).
* Added query slot scheduling for workloads, see [workload scheduling](/concepts/features/configuration/server-config/workload-scheduling#query_scheduling) for details. [#78415](https://github.com/ClickHouse/ClickHouse/pull/78415) ([Sergei Trifonov](https://github.com/serxa)).
* `timeSeries*` helper functions to speedup some scenarios when working with time series data: - re-sample the data to the time grid with specified start timestamp, end timestamp and step - calculate PromQL-like `delta`, `rate`, `idelta` and `irate`. [#80590](https://github.com/ClickHouse/ClickHouse/pull/80590) ([Alexander Gololobov](https://github.com/davenger)).
* Add `mapContainsValuesLike`/`mapContainsValues`/`mapExtractValuesLike` functions to filter on map values and their support in bloom filter based indexes. [#78171](https://github.com/ClickHouse/ClickHouse/pull/78171) ([UnamedRus](https://github.com/UnamedRus)).
* Now settings constraints can specify a set of disallowed values. [#78499](https://github.com/ClickHouse/ClickHouse/pull/78499) ([Bharat Nallan](https://github.com/bharatnc)).
* Added a setting `enable_shared_storage_snapshot_in_query` to enable sharing the same storage snapshot across all subqueries in a single query. This ensures consistent reads from the same table, even when the table is referenced multiple times within a query. [#79471](https://github.com/ClickHouse/ClickHouse/pull/79471) ([Amos Bird](https://github.com/amosbird)).
* Support writing `JSON` columns to `Parquet` and reading `JSON` columns from `Parquet` directly. [#79649](https://github.com/ClickHouse/ClickHouse/pull/79649) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Add `MultiPolygon` support for `pointInPolygon`. [#79773](https://github.com/ClickHouse/ClickHouse/pull/79773) ([Nihal Z. Miaji](https://github.com/nihalzp)).
* Add support for querying local filesystem-mounted Delta tables via `deltaLakeLocal` table function. [#79781](https://github.com/ClickHouse/ClickHouse/pull/79781) ([roykim98](https://github.com/roykim98)).
* Add new setting `cast_string_to_date_time_mode` that allows to choose DateTime parsing mode during cast from String. [#80210](https://github.com/ClickHouse/ClickHouse/pull/80210) ([Pavel Kruglov](https://github.com/Avogar)). For example, you can set it to the best effort mode.
* Added `bech32Encode` and `bech32Decode` functions for working with Bitcoin's Bech algorithm (issue [#40381](https://github.com/ClickHouse/ClickHouse/issues/40381)). [#80239](https://github.com/ClickHouse/ClickHouse/pull/80239) ([George Larionov](https://github.com/glarik)).
* Add SQL functions to analyse the names of MergeTree parts. [#80573](https://github.com/ClickHouse/ClickHouse/pull/80573) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Allow filtering parts selected for query by the disk they reside on by introducing a new virtual column, `_disk_name`. [#80650](https://github.com/ClickHouse/ClickHouse/pull/80650) ([tanner-bruce](https://github.com/tanner-bruce)).
* Add a landing page with the list of embedded web tools. It will open when requested by a browser-like user agent. [#81129](https://github.com/ClickHouse/ClickHouse/pull/81129) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Function `arrayFirst`, `arrayFirstIndex`, `arrayLast` and `arrayLastIndex` will filter away NULL values returned by the filter expression. In previous versions, Nullable filter results were not supported. Fixes [#81113](https://github.com/ClickHouse/ClickHouse/issues/81113). [#81197](https://github.com/ClickHouse/ClickHouse/pull/81197) ([Lennard Eijsackers](https://github.com/Blokje5)).
* It's now possible to write `USE DATABASE name` instead of `USE name`. [#81307](https://github.com/ClickHouse/ClickHouse/pull/81307) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Added a new system table `system.codecs` to introspect the available codecs. (issue [#81525](https://github.com/ClickHouse/ClickHouse/issues/81525)). [#81600](https://github.com/ClickHouse/ClickHouse/pull/81600) ([Jimmy Aguilar Mena](https://github.com/Ergus)).
* Support `lag` and `lead` window functions. Closes [#9887](https://github.com/ClickHouse/ClickHouse/issues/9887). [#82108](https://github.com/ClickHouse/ClickHouse/pull/82108) ([Dmitry Novik](https://github.com/novikd)).
* Function `tokens` now supports a new tokenizer, named `split`, which is good for logs. [#80195](https://github.com/ClickHouse/ClickHouse/pull/80195) ([Robert Schulze](https://github.com/rschu1ze)).
* Add support for the `--database` argument in `clickhouse-local`. You can switch to a previously created database. This closes [#44115](https://github.com/ClickHouse/ClickHouse/issues/44115). [#81465](https://github.com/ClickHouse/ClickHouse/pull/81465) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
#### Experimental Feature
* Implement Kafka rebalance like logic for `Kafka2` using ClickHouse Keeper For each replica we support two types of partition locks: permanent locks and temporary locks. The replica tries to hold permanent locks as long as possible, at any given time there are no more than `all_topic_partitions / active_replicas_count` (here `all_topic_partitions` is the number of all partitions, `active_replicas_count` is the number of active replicas) permanent locks on the replica, if there are more, then the replica releases some partitions. Some partitions are temporarily held by the replica. The maximum number of temporary locks on a replica changes dynamically to give other replicas a chance to take some partitions into permanent locks. When updating temporary locks, the replica releases them all and tries to take some others again. [#78726](https://github.com/ClickHouse/ClickHouse/pull/78726) ([Daria Fomina](https://github.com/sinfillo)).
* An improvement for the experimental text index: explicit parameters are supported via key-value pairs. Currently, supported parameters are a mandatory `tokenizer` and two optional `max_rows_per_postings_list` and `ngram_size`. [#80262](https://github.com/ClickHouse/ClickHouse/pull/80262) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Previously, `packed` storage was not supported for the full-text index, because the segment id was updated on-fly by reading and writing (`.gin_sid`) file on disk. In case of packed storage, reading a value from the uncommited file is not supported and this led to an issue. Now it is alright. [#80852](https://github.com/ClickHouse/ClickHouse/pull/80852) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Experimental indexes of type `gin` (which I don't like because it is an inside joke of PostgreSQL hackers) were renamed to `text`. Existing indexes of type `gin` remain loadable but they will throw an exception (suggesting `text` indexes instead) when one tries to use them in searches. [#80855](https://github.com/ClickHouse/ClickHouse/pull/80855) ([Robert Schulze](https://github.com/rschu1ze)).
#### Performance Improvement
* Enable multiple-projection filtering support, allowing to use more than one projection for part-level filtering. This addresses [#55525](https://github.com/ClickHouse/ClickHouse/issues/55525). This is the second step to implement projection index, following [#78429](https://github.com/ClickHouse/ClickHouse/issues/78429). [#80343](https://github.com/ClickHouse/ClickHouse/pull/80343) ([Amos Bird](https://github.com/amosbird)).
* Use `SLRU` cache policy in filesystem cache by default. [#75072](https://github.com/ClickHouse/ClickHouse/pull/75072) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Remove contention in the Resize step in query pipeline. [#77562](https://github.com/ClickHouse/ClickHouse/pull/77562) ([Zhiguo Zhou](https://github.com/ZhiguoZh)).
* Introduced an option to offload (de)compression and (de)serialization of blocks into pipeline threads instead of a single thread associated with a network connection. Controlled by the setting `enable_parallel_blocks_marshalling`. It should speed up distributed queries that transfer significant amounts of data between the initiator and remote nodes. [#78694](https://github.com/ClickHouse/ClickHouse/pull/78694) ([Nikita Taranov](https://github.com/nickitat)).
* Performance improvements to all bloom filter types. [Video from the OpenHouse conference](https://www.youtube.com/watch?v=yIVz0NKwQvA\&pp=ygUQb3BlbmhvdXNlIG9wZW5haQ%3D%3D) [#79800](https://github.com/ClickHouse/ClickHouse/pull/79800) ([Delyan Kratunov](https://github.com/dkratunov)).
* Introduced a happy path in `UniqExactSet::merge` when one of the sets is empty. Also, now if the LHS set is two-level and the RHS is single-level, we won't do the conversion to two-level for the RHS. [#79971](https://github.com/ClickHouse/ClickHouse/pull/79971) ([Nikita Taranov](https://github.com/nickitat)).
* Improve memory reuse efficiency and reduce page faults when using the two-level hash tables. This meant to speed-up GROUP BY. [#80245](https://github.com/ClickHouse/ClickHouse/pull/80245) ([Jiebin Sun](https://github.com/jiebinn)).
* Avoid unnecessary update and reduce lock contention in query condition cache. [#80247](https://github.com/ClickHouse/ClickHouse/pull/80247) ([Jiebin Sun](https://github.com/jiebinn)).
* Trivial optimization for `concatenateBlocks`. Chances are it's good for parallel hash join. [#80328](https://github.com/ClickHouse/ClickHouse/pull/80328) ([李扬](https://github.com/taiyang-li)).
* When selecting mark ranges from the primary key range, binary search cannot be used if the primary key is wrapped with functions. This PR improves this limitation: binary search can still be applied when the primary key is wrapped with an always monotonic function chain, or when the RPN contains an element that is always true. Closes [#45536](https://github.com/ClickHouse/ClickHouse/issues/45536). [#80597](https://github.com/ClickHouse/ClickHouse/pull/80597) ([zoomxi](https://github.com/zoomxi)).
* Improve shutdown speed of `Kafka` engine (remove extra 3 seconds delay in case of multiple `Kafka` tables). [#80796](https://github.com/ClickHouse/ClickHouse/pull/80796) ([Azat Khuzhin](https://github.com/azat)).
* Async inserts: reduce memory usage and improve performance of insert queries. [#80972](https://github.com/ClickHouse/ClickHouse/pull/80972) ([Raúl Marín](https://github.com/Algunenano)).
* Don't profile processors if the log table is disabled. [#81256](https://github.com/ClickHouse/ClickHouse/pull/81256) ([Raúl Marín](https://github.com/Algunenano)). This speeds up very short queries.
* Speed up `toFixedString` when the source is exactly what's requested. [#81257](https://github.com/ClickHouse/ClickHouse/pull/81257) ([Raúl Marín](https://github.com/Algunenano)).
* Don't process quota values if the user is not limited. [#81549](https://github.com/ClickHouse/ClickHouse/pull/81549) ([Raúl Marín](https://github.com/Algunenano)). This speeds up very short queries.
* Fixed performance regression in memory tracking. [#81694](https://github.com/ClickHouse/ClickHouse/pull/81694) ([Michael Kolupaev](https://github.com/al13n321)).
* Improve sharding key optimization on distributed query. [#78452](https://github.com/ClickHouse/ClickHouse/pull/78452) ([fhw12345](https://github.com/fhw12345)).
* Parallel replicas: avoid waiting for slow unused replicas if all read tasks have been assigned to other replicas. [#80199](https://github.com/ClickHouse/ClickHouse/pull/80199) ([Igor Nikonov](https://github.com/devcrafter)).
* Parallel replicas uses separate connection timeout, see `parallel_replicas_connect_timeout_ms` setting. Before `connect_timeout_with_failover_ms`/`connect_timeout_with_failover_secure_ms` settings were used as connection timeout values for parallel replicas queries (1 second by default). [#80421](https://github.com/ClickHouse/ClickHouse/pull/80421) ([Igor Nikonov](https://github.com/devcrafter)).
* In filesystem with journal `mkdir` is written to the journal of filesystem which is persisted to disk. In case of slow disk this can take long time. Move it out from reserve lock scope. [#81371](https://github.com/ClickHouse/ClickHouse/pull/81371) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Postpone reading of Iceberg manifest files until first reading query. [#81619](https://github.com/ClickHouse/ClickHouse/pull/81619) ([Daniil Ivanik](https://github.com/divanik)).
* Allow moving `GLOBAL [NOT] IN` predicate to `PREWHERE` clause if applicable. [#79996](https://github.com/ClickHouse/ClickHouse/pull/79996) ([Eduard Karacharov](https://github.com/korowa)).
#### Improvement
* `EXPLAIN SYNTAX` now uses a new analyzer. It returns AST built from the query tree. Added option `query_tree_passes` to control the number of passes to executed before converting query tree to the AST. [#74536](https://github.com/ClickHouse/ClickHouse/pull/74536) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Implement flattened serialization for Dynamic and JSON in Native format that allows to serialize/deserialize Dynamic and JSON data without special structures like shared variant for Dynamic and shared data for JSON. This serialization can be enabled by setting `output_format_native_use_flattened_dynamic_and_json_serialization`. This serialization can be used for easier support for Dynamic and JSON in TCP protocol in clients in different languages. [#80499](https://github.com/ClickHouse/ClickHouse/pull/80499) ([Pavel Kruglov](https://github.com/Avogar)).
* Refresh `S3` credentials after error `AuthenticationRequired`. [#77353](https://github.com/ClickHouse/ClickHouse/pull/77353) ([Vitaly Baranov](https://github.com/vitlibar)).
* Added dictionary metrics to `system.asynchronous_metrics` - `DictionaryMaxUpdateDelay` - the maximum delay (in seconds) of dictionary update. - `DictionaryTotalFailedUpdates` - the number of errors since last successful loading in all dictionaries. [#78175](https://github.com/ClickHouse/ClickHouse/pull/78175) ([Vlad](https://github.com/codeworse)).
* Add a warning about databases that were potentially created to save broken tables. [#78841](https://github.com/ClickHouse/ClickHouse/pull/78841) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Add `_time` virtual column in `S3Queue`, `AzureQueue` engine. [#78926](https://github.com/ClickHouse/ClickHouse/pull/78926) ([Anton Ivashkin](https://github.com/ianton-ru)).
* Make settings controlling connection drop on overloaded CPU hot-reloadable. [#79052](https://github.com/ClickHouse/ClickHouse/pull/79052) ([Alexey Katsman](https://github.com/alexkats)).
* Add container prefix to data paths reported in system.tables for plain disks in Azure blob storage, making reporting consistent with S3 and GCP. [#79241](https://github.com/ClickHouse/ClickHouse/pull/79241) ([Julia Kartseva](https://github.com/jkartseva)).
* Now, clickhouse-client and local also accept query parameters as `param-` (dash) along with `param_` (underscore). This closes [#63093](https://github.com/ClickHouse/ClickHouse/issues/63093). [#79429](https://github.com/ClickHouse/ClickHouse/pull/79429) ([Engel Danila](https://github.com/aaaengel)).
* Detailed warning msg for bandwidth discount when copying data from local to remote S3 with checksum enabled. [#79464](https://github.com/ClickHouse/ClickHouse/pull/79464) ([VicoWu](https://github.com/VicoWu)).
* Previously, when `input_format_parquet_max_block_size = 0` (an invalid value) ClickHouse would stuck. Now this behaviour is fixed. This closes [#79394](https://github.com/ClickHouse/ClickHouse/issues/79394). [#79601](https://github.com/ClickHouse/ClickHouse/pull/79601) ([abashkeev](https://github.com/abashkeev)).
* Add `throw_on_error` setting for `startup_scripts`: when `throw_on_error` is true, the server will not start unless all queries complete successfully. By default, `throw_on_error` is false, preserving the previous behavior. [#79732](https://github.com/ClickHouse/ClickHouse/pull/79732) ([Aleksandr Musorin](https://github.com/AVMusorin)).
* Allow to add `http_response_headers` in `http_handlers` of any kind. [#79975](https://github.com/ClickHouse/ClickHouse/pull/79975) ([Andrey Zvonov](https://github.com/zvonand)).
* Function `reverse` now supports `Tuple` data type. Closes [#80053](https://github.com/ClickHouse/ClickHouse/issues/80053). [#80083](https://github.com/ClickHouse/ClickHouse/pull/80083) ([flynn](https://github.com/ucasfl)).
* Resolve [#75817](https://github.com/ClickHouse/ClickHouse/issues/75817): allow getting `auxiliary_zookeepers` data from `system.zookeeper` table. [#80146](https://github.com/ClickHouse/ClickHouse/pull/80146) ([Nikolay Govorov](https://github.com/mrdimidium)).
* Add asynchronous metrics about the server's TCP sockets. This improves the observability. Closes [#80187](https://github.com/ClickHouse/ClickHouse/issues/80187). [#80188](https://github.com/ClickHouse/ClickHouse/pull/80188) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Support `anyLast_respect_nulls` and `any_respect_nulls` as a `SimpleAggregateFunction`. [#80219](https://github.com/ClickHouse/ClickHouse/pull/80219) ([Diskein](https://github.com/Diskein)).
* Remove unnecessary call `adjustCreateQueryForBackup` for replicated databases. [#80282](https://github.com/ClickHouse/ClickHouse/pull/80282) ([Vitaly Baranov](https://github.com/vitlibar)).
* Allow extra options (that go after `--` like `-- --config.value='abc'`) in `clickhouse-local` without the equality sign. Closes [#80292](https://github.com/ClickHouse/ClickHouse/issues/80292). [#80293](https://github.com/ClickHouse/ClickHouse/pull/80293) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Highlight metacharacters in `SHOW ... LIKE` queries. This closes [#80275](https://github.com/ClickHouse/ClickHouse/issues/80275). [#80297](https://github.com/ClickHouse/ClickHouse/pull/80297) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Make SQL UDF persistent in `clickhouse-local`. The previously created function will be loaded at startup. This closes [#80085](https://github.com/ClickHouse/ClickHouse/issues/80085). [#80300](https://github.com/ClickHouse/ClickHouse/pull/80300) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix description in explain plan for preliminary DISTINCT step. [#80330](https://github.com/ClickHouse/ClickHouse/pull/80330) ([UnamedRus](https://github.com/UnamedRus)).
* Allow to use named collections in ODBC/JDBC. [#80334](https://github.com/ClickHouse/ClickHouse/pull/80334) ([Andrey Zvonov](https://github.com/zvonand)).
* Metrics for number of readonly and broken disks. Indicator logs when DiskLocalCheckThread is started. [#80391](https://github.com/ClickHouse/ClickHouse/pull/80391) ([VicoWu](https://github.com/VicoWu)).
* Implement support for `s3_plain_rewritable` storage with projections. In previous versions, metadata objects in S3 referencing projections would not get updated when moved. Closes [#70258](https://github.com/ClickHouse/ClickHouse/issues/70258). [#80393](https://github.com/ClickHouse/ClickHouse/pull/80393) ([Sav](https://github.com/sberss)).
* The `SYSTEM UNFREEZE` command will not try to look up parts in readonly and write-once disks. This closes [#80430](https://github.com/ClickHouse/ClickHouse/issues/80430). [#80432](https://github.com/ClickHouse/ClickHouse/pull/80432) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Lowered the log level of merged parts messages. [#80476](https://github.com/ClickHouse/ClickHouse/pull/80476) ([Hans Krutzer](https://github.com/hkrutzer)).
* Change the default behavior of partition pruning for Iceberg tables. [#80583](https://github.com/ClickHouse/ClickHouse/pull/80583) ([Melvyn Peignon](https://github.com/melvynator)).
* Add two new ProfileEvents for index search algorithm observability: `IndexBinarySearchAlgorithm` and `IndexGenericExclusionSearchAlgorithm`. [#80679](https://github.com/ClickHouse/ClickHouse/pull/80679) ([Pablo Marcos](https://github.com/pamarcos)).
* Do not complain about unsupported `MADV_POPULATE_WRITE` for older kernels in logs (to avoid logs polluting). [#80704](https://github.com/ClickHouse/ClickHouse/pull/80704) ([Robert Schulze](https://github.com/rschu1ze)).
* Added support for `Date32` and `DateTime64` in `TTL` expressions. [#80710](https://github.com/ClickHouse/ClickHouse/pull/80710) ([Andrey Zvonov](https://github.com/zvonand)).
* Adjust compatibility values for `max_merge_delayed_streams_for_parallel_write`. [#80760](https://github.com/ClickHouse/ClickHouse/pull/80760) ([Azat Khuzhin](https://github.com/azat)).
* Fix a crash: if an exception is thrown in an attempt to remove a temporary file (they are used for spilling temporary data on disk) in the destructor, the program can terminate. [#80776](https://github.com/ClickHouse/ClickHouse/pull/80776) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add `IF EXISTS` modifier to `SYSTEM SYNC REPLICA`. [#80810](https://github.com/ClickHouse/ClickHouse/pull/80810) ([Raúl Marín](https://github.com/Algunenano)).
* Extend exception message about "Having zero bytes, but read range is not finished...", add finished\_download\_time column to `system.filesystem_cache`. [#80849](https://github.com/ClickHouse/ClickHouse/pull/80849) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Add search algorithm section to `EXPLAIN` output when using it with indexes = 1. If shows either "binary search" or "generic exclusion search". [#80881](https://github.com/ClickHouse/ClickHouse/pull/80881) ([Pablo Marcos](https://github.com/pamarcos)).
* At the beginning of 2024, `prefer_column_name_to_alias` was hardcoded to true for MySQL handler because the new analyzer was not enabled by default. Now, it can be unhardcoded. [#80916](https://github.com/ClickHouse/ClickHouse/pull/80916) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Now `system.iceberg_history` shows history for catalogs databases like glue or iceberg rest. Also renamed `table_name` and `database_name` columns to `table` and `database` in `system.iceberg_history` for consistency. [#80975](https://github.com/ClickHouse/ClickHouse/pull/80975) ([alesapin](https://github.com/alesapin)).
* Allow read-only mode for the `merge` table function, so the `CREATE TEMPORARY TABLE` grant is not required for using it. [#80981](https://github.com/ClickHouse/ClickHouse/pull/80981) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Better introspection of in-memory caches (expose information about caches in `system.metrics` over incomplete `system.asynchronouse_metrics`). Add in-memory caches size (in bytes) into `dashboard.html`. `VectorSimilarityIndexCacheSize`/`IcebergMetadataFilesCacheSize` has been renamed to `VectorSimilarityIndexCacheBytes`/`IcebergMetadataFilesCacheBytes`. [#81023](https://github.com/ClickHouse/ClickHouse/pull/81023) ([Azat Khuzhin](https://github.com/azat)).
* Ignore databases with engines that can't contain `RocksDB` tables while reading from `system.rocksdb`. [#81083](https://github.com/ClickHouse/ClickHouse/pull/81083) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Allow `filesystem_caches` and `named_collections` in the `clickhouse-local` configuration file. [#81105](https://github.com/ClickHouse/ClickHouse/pull/81105) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix highlighting of `PARTITION BY` in `INSERT` queries. In previous versions, `PARTITION BY` was not highlighted as a keyword. [#81106](https://github.com/ClickHouse/ClickHouse/pull/81106) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Two mini improvements in Web UI: - correctly handle queries without output, such as `CREATE`, `INSERT` (until recently, these queries resulted in an infinite spinner); - when double clicking on a table, scroll to the top. [#81131](https://github.com/ClickHouse/ClickHouse/pull/81131) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* `MemoryResidentWithoutPageCache` metric provides the amount of physical memory used by the server process, excluding userspace page cache, in bytes. This provides a more accurate view of actual memory usage when userspace page cache is utilized. When userspace page cache is disabled, this value equals `MemoryResident`. [#81233](https://github.com/ClickHouse/ClickHouse/pull/81233) ([Jayme Bird](https://github.com/jaymebrd)).
* Mark manually logged exceptions in client, local server, keeper client and disks app as logged, so that they are not logged twice. [#81271](https://github.com/ClickHouse/ClickHouse/pull/81271) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Setting `use_skip_indexes_if_final` and `use_skip_indexes_if_final_exact_mode` now default to `True`. Queries with `FINAL` clause will now use skip indexes (if applicable) to shortlist granules and also read any additional granules corresponding to matching primary key ranges. Users needing earlier behaviour of approximate/imprecise results can set `use_skip_indexes_if_final_exact_mode` to FALSE after careful evaluation. [#81331](https://github.com/ClickHouse/ClickHouse/pull/81331) ([Shankar Iyer](https://github.com/shankar-iyer)).
* When you have multiple queries in the web UI, it will run the one under the cursor. Continuation of [#80977](https://github.com/ClickHouse/ClickHouse/issues/80977). [#81354](https://github.com/ClickHouse/ClickHouse/pull/81354) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* This PR addresses issues with the implementation of `is_strict` in the monotonicity checks for conversion functions. Currently, some conversion functions, such as `toFloat64(UInt32)` and `toDate(UInt8)`, incorrectly return `is_strict` as false when they should return true. [#81359](https://github.com/ClickHouse/ClickHouse/pull/81359) ([zoomxi](https://github.com/zoomxi)).
* When checking if a `KeyCondition` matches a continuous range, if the key is wrapped with a non-strict function chain, a `Constraint::POINT` may needs to be converted to a`Constraint::RANGE`. For example: `toDate(event_time) = '2025-06-03'` implies a range for `event_time`: \['2025-06-03 00:00:00', '2025-06-04 00:00:00'). This PR fixes this behavior. [#81400](https://github.com/ClickHouse/ClickHouse/pull/81400) ([zoomxi](https://github.com/zoomxi)).
* `clickhouse`/`ch` aliases will invoke `clickhouse-client` instead of `clickhouse-local` if `--host` or `--port` are specified. Continuation of [#79422](https://github.com/ClickHouse/ClickHouse/issues/79422). Closes [#65252](https://github.com/ClickHouse/ClickHouse/issues/65252). [#81509](https://github.com/ClickHouse/ClickHouse/pull/81509) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Now that we have the keeper response time distribution data, we can tune the histogram buckets for metrics. [#81516](https://github.com/ClickHouse/ClickHouse/pull/81516) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Add profile event `PageCacheReadBytes`. [#81742](https://github.com/ClickHouse/ClickHouse/pull/81742) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix logical error in filesystem cache: "Having zero bytes but range is not finished". [#81868](https://github.com/ClickHouse/ClickHouse/pull/81868) ([Kseniia Sumarokova](https://github.com/kssenii)).
#### Bug Fix (user-visible misbehavior in an official stable release)
* Fix parameterized view with SELECT EXCEPT query. Closes [#49447](https://github.com/ClickHouse/ClickHouse/issues/49447). [#57380](https://github.com/ClickHouse/ClickHouse/pull/57380) ([Nikolay Degterinsky](https://github.com/evillique)).
* Analyzer: Fix column projection name after column type promotion in join. Closes [#63345](https://github.com/ClickHouse/ClickHouse/issues/63345). [#63519](https://github.com/ClickHouse/ClickHouse/pull/63519) ([Dmitry Novik](https://github.com/novikd)).
* Fixed a logical error in cases of column name clashes when analyzer\_compatibility\_join\_using\_top\_level\_identifier is enabled. [#75676](https://github.com/ClickHouse/ClickHouse/pull/75676) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix CTE usage in pushed-down predicates when `allow_push_predicate_ast_for_distributed_subqueries` is enabled. Fixes [#75647](https://github.com/ClickHouse/ClickHouse/issues/75647). Fixes [#79672](https://github.com/ClickHouse/ClickHouse/issues/79672). [#77316](https://github.com/ClickHouse/ClickHouse/pull/77316) ([Dmitry Novik](https://github.com/novikd)).
* Fixes an issue where SYSTEM SYNC REPLICA LIGHTWEIGHT 'foo' would report success even when the specified replica didn't exist. The command now properly validates that the replica exists in Keeper before attempting synchronization. [#78405](https://github.com/ClickHouse/ClickHouse/pull/78405) ([Jayme Bird](https://github.com/jaymebrd)).
* Fix crash for a very specific situation when the `currentDatabase` function was used in `CONSTRAINT` sections for `ON CLUSTER` queries Closes [#78100](https://github.com/ClickHouse/ClickHouse/issues/78100). [#79070](https://github.com/ClickHouse/ClickHouse/pull/79070) ([pufit](https://github.com/pufit)).
* Fix passing of external roles in interserver queries. [#79099](https://github.com/ClickHouse/ClickHouse/pull/79099) ([Andrey Zvonov](https://github.com/zvonand)).
* Try to use IColumn instead of Field in SingleValueDataGeneric. It fixes the incorrect return values for some aggregate functions like `argMax` for types `Dynamic/Variant/JSON`. [#79166](https://github.com/ClickHouse/ClickHouse/pull/79166) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix applying use\_native\_copy and allow\_azure\_native\_copy setting for azure blob storage and updated to use native copy only when credentials match resolves [#78964](https://github.com/ClickHouse/ClickHouse/issues/78964). [#79561](https://github.com/ClickHouse/ClickHouse/pull/79561) ([Smita Kulkarni](https://github.com/SmitaRKulkarni)).
* Fix logical errors about a column's unknown origin scope produced while checking if this column is correlated. Fixes [#78183](https://github.com/ClickHouse/ClickHouse/issues/78183). Fixes [#79451](https://github.com/ClickHouse/ClickHouse/issues/79451). [#79727](https://github.com/ClickHouse/ClickHouse/pull/79727) ([Dmitry Novik](https://github.com/novikd)).
* Fix wrong results for grouping sets with ColumnConst and Analyzer. [#79743](https://github.com/ClickHouse/ClickHouse/pull/79743) ([Andrey Zvonov](https://github.com/zvonand)).
* Fix local shard result duplication when reading from distributed table with local replica being stale. [#79761](https://github.com/ClickHouse/ClickHouse/pull/79761) ([Eduard Karacharov](https://github.com/korowa)).
* Fix the sorting order of the NaNs with a negative sign bit. [#79847](https://github.com/ClickHouse/ClickHouse/pull/79847) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Now GROUP BY ALL doesn't take into account the GROUPING part. [#79915](https://github.com/ClickHouse/ClickHouse/pull/79915) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Fixed incorrect state merging for `TopK` / `TopKWeighted` functions that would cause excessive error values even when capacity was not exhausted. [#79939](https://github.com/ClickHouse/ClickHouse/pull/79939) ([Joel Höner](https://github.com/athre0z)).
* Respect `readonly` setting in `azure_blob_storage` object storage. [#79954](https://github.com/ClickHouse/ClickHouse/pull/79954) ([Julia Kartseva](https://github.com/jkartseva)).
* Fixed incorrect query results and out-of-memory crashes when using `match(column, '^…')` with backslash-escaped characters. [#79969](https://github.com/ClickHouse/ClickHouse/pull/79969) ([filimonov](https://github.com/filimonov)).
* Disabling hive partitioning for datalakes Partially addresses [https://github.com/issues/assigned?issue=ClickHouse%7CClickHouse%7C79937](https://github.com/issues/assigned?issue=ClickHouse%7CClickHouse%7C79937). [#80005](https://github.com/ClickHouse/ClickHouse/pull/80005) ([Daniil Ivanik](https://github.com/divanik)).
* Skip indexes with lambda expressions could not be applied. Fix the case when high-level functions in the index definition exactly match the one in the query. [#80025](https://github.com/ClickHouse/ClickHouse/pull/80025) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fix metadata version during attach part on the replica executing ATTACH\_PART command from replication log. [#80038](https://github.com/ClickHouse/ClickHouse/pull/80038) ([Aleksei Filatov](https://github.com/aalexfvk)).
* Executable User Defined Functions (eUDF) names are not added to the `used_functions` column of the `system.query_log` table, unlike other functions. This PR implements the addition of the eUDF name if the eUDF was used in the request. [#80073](https://github.com/ClickHouse/ClickHouse/pull/80073) ([Kyamran](https://github.com/nibblerenush)).
* Fix logical error in Arrow format with LowCardinality(FixedString). [#80156](https://github.com/ClickHouse/ClickHouse/pull/80156) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix reading subcolumns from Merge engine. [#80158](https://github.com/ClickHouse/ClickHouse/pull/80158) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix a bug about the comparison between numeric types in `KeyCondition`. [#80207](https://github.com/ClickHouse/ClickHouse/pull/80207) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Fix AMBIGUOUS\_COLUMN\_NAME when lazy materialization applied to table with projections. [#80251](https://github.com/ClickHouse/ClickHouse/pull/80251) ([Igor Nikonov](https://github.com/devcrafter)).
* Fix incorrect count optimization for string prefix filters like LIKE 'ab\_c%' when using implicit projections. This fixes [#80250](https://github.com/ClickHouse/ClickHouse/issues/80250). [#80261](https://github.com/ClickHouse/ClickHouse/pull/80261) ([Amos Bird](https://github.com/amosbird)).
* Fix improper serialization of nested numeric fields as strings in MongoDB documents. Remove maximum depth limit for documents from MongoDB. [#80289](https://github.com/ClickHouse/ClickHouse/pull/80289) ([Kirill Nikiforov](https://github.com/allmazz)).
* Perform less strict metadata checks for RMT in the Replicated database. Closes [#80296](https://github.com/ClickHouse/ClickHouse/issues/80296). [#80298](https://github.com/ClickHouse/ClickHouse/pull/80298) ([Nikolay Degterinsky](https://github.com/evillique)).
* Fix text representation of DateTime and DateTime64 for PostgreSQL storage. [#80301](https://github.com/ClickHouse/ClickHouse/pull/80301) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Allow `DateTime` with timezone in `StripeLog` tables. This closes [#44120](https://github.com/ClickHouse/ClickHouse/issues/44120). [#80304](https://github.com/ClickHouse/ClickHouse/pull/80304) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Disable filter-push-down for the predicate with a non-deterministic function in case the query plan step changes the number of rows. Fixes [#40273](https://github.com/ClickHouse/ClickHouse/issues/40273). [#80329](https://github.com/ClickHouse/ClickHouse/pull/80329) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fix possible logical errors and crashes in projections with subcolumns. [#80333](https://github.com/ClickHouse/ClickHouse/pull/80333) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix `NOT_FOUND_COLUMN_IN_BLOCK` error caused by filter-push-down optimization of the logical JOIN sep in case `ON` expression is not a trivial equality. Fixes [#79647](https://github.com/ClickHouse/ClickHouse/issues/79647) Fixes [#77848](https://github.com/ClickHouse/ClickHouse/issues/77848). [#80360](https://github.com/ClickHouse/ClickHouse/pull/80360) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fix incorrect result when reading reverse-ordered keys in partitioned tables. This fixes [#79987](https://github.com/ClickHouse/ClickHouse/issues/79987). [#80448](https://github.com/ClickHouse/ClickHouse/pull/80448) ([Amos Bird](https://github.com/amosbird)).
* Fixed wrong sorting in tables with a nullable key and enabled optimize\_read\_in\_order. [#80515](https://github.com/ClickHouse/ClickHouse/pull/80515) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Fixed refreshable materialized view DROP getting stuck if the view was paused using SYSTEM STOP REPLICATED VIEW. [#80543](https://github.com/ClickHouse/ClickHouse/pull/80543) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix 'Cannot find column' with constant tuple in distributed query. [#80596](https://github.com/ClickHouse/ClickHouse/pull/80596) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Fix `shardNum` function in Distributed tables with `join_use_nulls`. [#80612](https://github.com/ClickHouse/ClickHouse/pull/80612) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Fix incorrect result during reading column that exists in subset of tables in Merge engine. [#80643](https://github.com/ClickHouse/ClickHouse/pull/80643) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix possible SSH protocol (due to hang in replxx). [#80688](https://github.com/ClickHouse/ClickHouse/pull/80688) ([Azat Khuzhin](https://github.com/azat)).
* The timestamp in the iceberg\_history table should now be correct. [#80711](https://github.com/ClickHouse/ClickHouse/pull/80711) ([Melvyn Peignon](https://github.com/melvynator)).
* Fix possible crash in case of dictionary registration failed (when `CREATE DICTIONARY` failed with `CANNOT_SCHEDULE_TASK` it is possible to leave dangling pointer in the dictionary registry, which later lead to crash). [#80714](https://github.com/ClickHouse/ClickHouse/pull/80714) ([Azat Khuzhin](https://github.com/azat)).
* Fix handling of enum globs of a single element in object storage table functions. [#80716](https://github.com/ClickHouse/ClickHouse/pull/80716) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fix wrong result type of comparison functions with Tuple(Dynamic) and String that led to logical error. [#80728](https://github.com/ClickHouse/ClickHouse/pull/80728) ([Pavel Kruglov](https://github.com/Avogar)).
* Add missing support data type `timestamp_ntz` for unity catalog. Fixes [#79535](https://github.com/ClickHouse/ClickHouse/issues/79535), Fixes [#79875](https://github.com/ClickHouse/ClickHouse/issues/79875). [#80740](https://github.com/ClickHouse/ClickHouse/pull/80740) ([alesapin](https://github.com/alesapin)).
* Fix `THERE_IS_NO_COLUMN` error for distributed queries with `IN cte`. Fixes [#75032](https://github.com/ClickHouse/ClickHouse/issues/75032). [#80757](https://github.com/ClickHouse/ClickHouse/pull/80757) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fix excessive number of files (leads to excessive memory usage) for external ORDER BY. [#80777](https://github.com/ClickHouse/ClickHouse/pull/80777) ([Azat Khuzhin](https://github.com/azat)).
* This PR might close [#80742](https://github.com/ClickHouse/ClickHouse/issues/80742). [#80783](https://github.com/ClickHouse/ClickHouse/pull/80783) ([zoomxi](https://github.com/zoomxi)).
* Fix crash in Kafka due to get\_member\_id() was creating std::string from NULL (it was likely an issue only in case of connection to broker had been failed). [#80793](https://github.com/ClickHouse/ClickHouse/pull/80793) ([Azat Khuzhin](https://github.com/azat)).
* Properly wait consumers before shutting down Kafka engine (active consumers after shutdown can trigger various debug assertions and also may read data from brokers in background after table has been dropped/detached). [#80795](https://github.com/ClickHouse/ClickHouse/pull/80795) ([Azat Khuzhin](https://github.com/azat)).
* Fix `NOT_FOUND_COLUMN_IN_BLOCK`, which is caused by `predicate-push-down` optimization. Fixes [#80443](https://github.com/ClickHouse/ClickHouse/issues/80443). [#80834](https://github.com/ClickHouse/ClickHouse/pull/80834) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fix logical error when resolving star (\*) matcher in table function in JOIN with USING. [#80894](https://github.com/ClickHouse/ClickHouse/pull/80894) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix memory accounting for Iceberg metadata files cache. [#80904](https://github.com/ClickHouse/ClickHouse/pull/80904) ([Azat Khuzhin](https://github.com/azat)).
* Fix wrong partitioning with nullable partition key. [#80913](https://github.com/ClickHouse/ClickHouse/pull/80913) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Fix `Table does not exist` error for distributed queries with pushed-down predicate (`allow_push_predicate_ast_for_distributed_subqueries=1`) when the source table does not exist on the initialtor. Fixes [#77281](https://github.com/ClickHouse/ClickHouse/issues/77281). [#80915](https://github.com/ClickHouse/ClickHouse/pull/80915) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fix the logical error in the nested functions with named windows. [#80926](https://github.com/ClickHouse/ClickHouse/pull/80926) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Fix extremes for nullable and floating-point columns. [#80970](https://github.com/ClickHouse/ClickHouse/pull/80970) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Fix possible crash while querying from system.tables (likely the case under memory pressure). [#80976](https://github.com/ClickHouse/ClickHouse/pull/80976) ([Azat Khuzhin](https://github.com/azat)).
* Fix atomic rename with truncate for files which compression is inferred from their file extension. [#80979](https://github.com/ClickHouse/ClickHouse/pull/80979) ([Pablo Marcos](https://github.com/pamarcos)).
* Fix ErrorCodes::getName. [#81032](https://github.com/ClickHouse/ClickHouse/pull/81032) ([RinChanNOW](https://github.com/RinChanNOWWW)).
* Fix bug when user cannot list tables in Unity Catalog without permissions for all of them. Now all tables are listed properly, attempt to read from restricted table will throw an exception. [#81044](https://github.com/ClickHouse/ClickHouse/pull/81044) ([alesapin](https://github.com/alesapin)).
* Now ClickHouse will ignore errors and unexpected responses from data lake catalogs in `SHOW TABLES` query. Fixes [#79725](https://github.com/ClickHouse/ClickHouse/issues/79725). [#81046](https://github.com/ClickHouse/ClickHouse/pull/81046) ([alesapin](https://github.com/alesapin)).
* Fix parsing of DateTime64 from integers in JSONExtract and JSON type parsing. [#81050](https://github.com/ClickHouse/ClickHouse/pull/81050) ([Pavel Kruglov](https://github.com/Avogar)).
* Reflect date\_time\_input\_format setting in schema inference cache. [#81052](https://github.com/ClickHouse/ClickHouse/pull/81052) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix crash on INSERT if table was DROPed after query started but before columns sent. [#81053](https://github.com/ClickHouse/ClickHouse/pull/81053) ([Azat Khuzhin](https://github.com/azat)).
* Fix use-of-uninitialized-value in quantileDeterministic. [#81062](https://github.com/ClickHouse/ClickHouse/pull/81062) ([Azat Khuzhin](https://github.com/azat)).
* Fix hardlinks count management for metadatastoragefromdisk disk transactions. add tests. [#81066](https://github.com/ClickHouse/ClickHouse/pull/81066) ([Sema Checherinda](https://github.com/CheSema)).
* User Defined Functions (UDF) names are not added to the `system.query_log` table, unlike other functions. This PR implements the addition of the UDF name to one of the two columns `used_executable_user_defined_functions` or `used_sql_user_defined_functions` if the UDF was used in the request. [#81101](https://github.com/ClickHouse/ClickHouse/pull/81101) ([Kyamran](https://github.com/nibblerenush)).
* Fixed `Too large size ... passed to allocator` errors or possible crashes on inserts via http protocol with text formats (`JSON`, `Values`, ...) and omitted `Enum` fields. [#81145](https://github.com/ClickHouse/ClickHouse/pull/81145) ([Anton Popov](https://github.com/CurtizJ)).
* Fix LOGICAL\_ERROR in case of Sparse column in INSERT block pushed to non-MT MV. [#81161](https://github.com/ClickHouse/ClickHouse/pull/81161) ([Azat Khuzhin](https://github.com/azat)).
* Fix `Unknown table expression identifier` for `distributed_product_mode_local=local` with cross-replication. [#81162](https://github.com/ClickHouse/ClickHouse/pull/81162) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fixed incorrectly caching number of rows in parquet files after filtering. [#81184](https://github.com/ClickHouse/ClickHouse/pull/81184) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix fs cache max\_size\_to\_total\_space setting when used with relative cache path. [#81237](https://github.com/ClickHouse/ClickHouse/pull/81237) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fixed clickhouse-local crashing when outputting const tuples or maps in Parquet format. [#81249](https://github.com/ClickHouse/ClickHouse/pull/81249) ([Michael Kolupaev](https://github.com/al13n321)).
* Verify array offsets received over network. [#81269](https://github.com/ClickHouse/ClickHouse/pull/81269) ([Azat Khuzhin](https://github.com/azat)).
* Fix some corner case in query that joins empty tables and uses window functions. The bug leads to exploding number of parallel streams which leads to OOMs. [#81299](https://github.com/ClickHouse/ClickHouse/pull/81299) ([Alexander Gololobov](https://github.com/davenger)).
* Fixes for datalake Cluster functions (`deltaLakeCluster`, `icebergCluster`, etc): (1) fix potential segfault in `DataLakeConfiguration` when using `Cluster` function with old analyzer; (2) remove duplicating data lake metadata updates (extra object storage requests); (3) fix redundant listing in object storage when format is not explicitly specified (which was already done for non-cluster data lake engines). [#81300](https://github.com/ClickHouse/ClickHouse/pull/81300) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Make force\_restore\_data flag recover lost keeper metadata. [#81324](https://github.com/ClickHouse/ClickHouse/pull/81324) ([Raúl Marín](https://github.com/Algunenano)).
* Fix region error in delta-kernel. Fixes [#79914](https://github.com/ClickHouse/ClickHouse/issues/79914). [#81353](https://github.com/ClickHouse/ClickHouse/pull/81353) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Disable incorrect JIT for divideOrNull. [#81370](https://github.com/ClickHouse/ClickHouse/pull/81370) ([Raúl Marín](https://github.com/Algunenano)).
* Fix insert error when MergeTree table has a long partition column name. [#81390](https://github.com/ClickHouse/ClickHouse/pull/81390) ([hy123q](https://github.com/haoyangqian)).
* Backported in [#81957](https://github.com/ClickHouse/ClickHouse/issues/81957): Fixed possible crash in `Aggregator` in case of exception during merge. [#81450](https://github.com/ClickHouse/ClickHouse/pull/81450) ([Nikita Taranov](https://github.com/nickitat)).
* Don't store content of several manifest files in memory. [#81470](https://github.com/ClickHouse/ClickHouse/pull/81470) ([Daniil Ivanik](https://github.com/divanik)).
* Fix possible crash during shutting down background pools (`background_.*pool_size`). [#81473](https://github.com/ClickHouse/ClickHouse/pull/81473) ([Azat Khuzhin](https://github.com/azat)).
* Fix out-of-bounds read in the `Npy` format happening when writing to a table with the `URL` engine. This closes [#81356](https://github.com/ClickHouse/ClickHouse/issues/81356). [#81502](https://github.com/ClickHouse/ClickHouse/pull/81502) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* There is a chance that Web UI displays `NaN%` (typical JavaScript problems). [#81507](https://github.com/ClickHouse/ClickHouse/pull/81507) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix `DatabaseReplicated` for `database_replicated_enforce_synchronous_settings=1`. [#81564](https://github.com/ClickHouse/ClickHouse/pull/81564) ([Azat Khuzhin](https://github.com/azat)).
* Fix sorting order for LowCardinality(Nullable(...)) types. [#81583](https://github.com/ClickHouse/ClickHouse/pull/81583) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Server should not preserve a HTTP connection if the request has not been fully read from the socket. [#81595](https://github.com/ClickHouse/ClickHouse/pull/81595) ([Sema Checherinda](https://github.com/CheSema)).
* Make scalar correlated subqueries return a nullable result of the projection expression. Fix the case when a correlated subquery produces an empty result set. [#81632](https://github.com/ClickHouse/ClickHouse/pull/81632) ([Dmitry Novik](https://github.com/novikd)).
* Fix `Unexpected relative path for a deduplicated part` during `ATTACH` to `ReplicatedMergeTree`. [#81647](https://github.com/ClickHouse/ClickHouse/pull/81647) ([Azat Khuzhin](https://github.com/azat)).
* Query settings `use_iceberg_partition_pruning` will not take effect for iceberg storage, because it uses global context rather than query context. it's not critical because its default value is true. this pr can fix it. [#81673](https://github.com/ClickHouse/ClickHouse/pull/81673) ([Han Fei](https://github.com/hanfei1991)).
* Backported in [#82128](https://github.com/ClickHouse/ClickHouse/issues/82128): Fix "Context has expired" during merges when dict used in TTL expression. [#81690](https://github.com/ClickHouse/ClickHouse/pull/81690) ([Azat Khuzhin](https://github.com/azat)).
* Add validation for mergetree setting `merge_max_block_size` to ensure that it's non zero. [#81693](https://github.com/ClickHouse/ClickHouse/pull/81693) ([Bharat Nallan](https://github.com/bharatnc)).
* Fix issues with `clickhouse-local` involving stuck `DROP VIEW ` queries. [#81705](https://github.com/ClickHouse/ClickHouse/pull/81705) ([Bharat Nallan](https://github.com/bharatnc)).
* Fix StorageRedis join in some cases. [#81736](https://github.com/ClickHouse/ClickHouse/pull/81736) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Fix crash in `ConcurrentHashJoin` with empty `USING ()` and old analyzer enabled. [#81754](https://github.com/ClickHouse/ClickHouse/pull/81754) ([Nikita Taranov](https://github.com/nickitat)).
* Keeper fix: block commits of new logs if there is invalid entry in the logs. Previously, if leader applied some logs incorrectly, it would continue to commit new logs, even though the follower would detect digest mismatch and abort. [#81780](https://github.com/ClickHouse/ClickHouse/pull/81780) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix the issue where required columns are not read during scalar correlated subquery processing. Fixes [#81716](https://github.com/ClickHouse/ClickHouse/issues/81716). [#81805](https://github.com/ClickHouse/ClickHouse/pull/81805) ([Dmitry Novik](https://github.com/novikd)).
* Someone littered our code with Kusto. Cleaned it up. This closes [#81643](https://github.com/ClickHouse/ClickHouse/issues/81643). [#81885](https://github.com/ClickHouse/ClickHouse/pull/81885) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* In previous versions, the server returned excessive content for requests to `/js`. This closes [#61890](https://github.com/ClickHouse/ClickHouse/issues/61890). [#81895](https://github.com/ClickHouse/ClickHouse/pull/81895) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Previously, `MongoDB` table engine definitions could include a path component in the `host:port` argument which was silently ignored. The mongodb integration refuses to load such tables. With this fix *we allow loading such tables and ignore path component* if `MongoDB` engine has five arguments, using the database name from arguments. *Note:* The fix is not applied for newly created tables or queries with `mongo` table function, as well as for dictionary sources and named collections. [#81942](https://github.com/ClickHouse/ClickHouse/pull/81942) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fixed possible crash in `Aggregator` in case of exception during merge. [#82022](https://github.com/ClickHouse/ClickHouse/pull/82022) ([Nikita Taranov](https://github.com/nickitat)).
* Fixing copy-paste error in `arraySimilarity`, disallowing the use of `UInt32` and `Int32` weights. Update tests and docs. [#82103](https://github.com/ClickHouse/ClickHouse/pull/82103) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
* Fix possible data-race between suggestion thread and main client thread. [#82233](https://github.com/ClickHouse/ClickHouse/pull/82233) ([Azat Khuzhin](https://github.com/azat)).
#### Build/Testing/Packaging Improvement
* Use `postgres` 16.9. [#81437](https://github.com/ClickHouse/ClickHouse/pull/81437) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Use `openssl` 3.2.4. [#81438](https://github.com/ClickHouse/ClickHouse/pull/81438) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Use `abseil-cpp` 2025-01-27. [#81440](https://github.com/ClickHouse/ClickHouse/pull/81440) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Use `mongo-c-driver` 1.30.4. [#81449](https://github.com/ClickHouse/ClickHouse/pull/81449) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Use `krb5` 1.21.3-final. [#81453](https://github.com/ClickHouse/ClickHouse/pull/81453) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Use `orc` 2.1.2. [#81455](https://github.com/ClickHouse/ClickHouse/pull/81455) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Use `grpc` 1.73.0. [#81629](https://github.com/ClickHouse/ClickHouse/pull/81629) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Use `delta-kernel-rs` v0.12.1. [#81707](https://github.com/ClickHouse/ClickHouse/pull/81707) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Update `c-ares` to `v1.34.5`. [#81159](https://github.com/ClickHouse/ClickHouse/pull/81159) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Upgrade `curl` to 8.14 to address CVE-2025-5025 and CVE-2025-4947. [#81171](https://github.com/ClickHouse/ClickHouse/pull/81171) ([larryluogit](https://github.com/larryluogit)).
* Upgrade `libarchive` to 3.7.9 to address: CVE-2024-20696 CVE-2025-25724 CVE-2024-48958 CVE-2024-57970 CVE-2025-1632 CVE-2024-48957 CVE-2024-48615. [#81174](https://github.com/ClickHouse/ClickHouse/pull/81174) ([larryluogit](https://github.com/larryluogit)).
* Upgrade `libxml2` to 2.14.3. [#81187](https://github.com/ClickHouse/ClickHouse/pull/81187) ([larryluogit](https://github.com/larryluogit)).
* Avoid copying vendored Rust sources to `CARGO_HOME`. [#79560](https://github.com/ClickHouse/ClickHouse/pull/79560) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Remove dependency on the Sentry library by replacing it with our own endpoint. [#80236](https://github.com/ClickHouse/ClickHouse/pull/80236) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Update python dependencies in CI images to address Dependabot alerts. [#80658](https://github.com/ClickHouse/ClickHouse/pull/80658) ([Raúl Marín](https://github.com/Algunenano)).
* Retry reading of replicated DDL stop flag from Keeper at startup to make tests more robust when fault injection is enabled for Keeper. [#80964](https://github.com/ClickHouse/ClickHouse/pull/80964) ([Alexander Gololobov](https://github.com/davenger)).
* Use https for ubuntu archive url. [#81016](https://github.com/ClickHouse/ClickHouse/pull/81016) ([Raúl Marín](https://github.com/Algunenano)).
* Update python dependencies in test images. [#81042](https://github.com/ClickHouse/ClickHouse/pull/81042) ([dependabot\[bot\]](https://github.com/apps/dependabot)).
* Introduce `flake.nix` for Nix builds. [#81463](https://github.com/ClickHouse/ClickHouse/pull/81463) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fix `delta-kernel-rs` requiring network access during build. Closes [#80609](https://github.com/ClickHouse/ClickHouse/issues/80609). [#81602](https://github.com/ClickHouse/ClickHouse/pull/81602) ([Konstantin Bogdanov](https://github.com/thevar1able)). Read the article [A Year of Rust in ClickHouse](https://clickhouse.com/blog/rust).
ClickHouse release 25.5, 2025-05-22
#### Backward Incompatible Change
* Function `geoToH3` now accepts the input in the order (lat, lon, res) (which is common for other geometric functions). Users who wish to retain the previous result order (lon, lat, res) can set setting `geotoh3_argument_order = 'lon_lat'`. [#78852](https://github.com/ClickHouse/ClickHouse/pull/78852) ([Pratima Patel](https://github.com/pratimapatel2008)).
* Add a filesystem cache setting `allow_dynamic_cache_resize`, by default `false`, to allow dynamic resize of filesystem cache. Why: in certain environments (ClickHouse Cloud) all the scaling events happen through the restart of the process and we would love this feature to be explicitly disabled to have more control over the behaviour + as a safety measure. This PR is marked as backward incompatible, because in older versions dynamic cache resize worked by default without special setting. [#79148](https://github.com/ClickHouse/ClickHouse/pull/79148) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Removed support for legacy index types `annoy` and `usearch`. Both have been stubs for a long time, i.e. every attempt to use the legacy indexes returned an error anyways. If you still have `annoy` and `usearch` indexes, please drop them. [#79802](https://github.com/ClickHouse/ClickHouse/pull/79802) ([Robert Schulze](https://github.com/rschu1ze)).
* Remove `format_alter_commands_with_parentheses` server setting. The setting was introduced and disabled by default in 24.2. It was enabled by default in 25.2. As there are no LTS versions that don't support the new format, we can remove the setting. [#79970](https://github.com/ClickHouse/ClickHouse/pull/79970) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Enable `DeltaLake` storage `delta-kernel-rs` implementation by default. [#79541](https://github.com/ClickHouse/ClickHouse/pull/79541) ([Kseniia Sumarokova](https://github.com/kssenii)).
* If reading from an `URL` involves multiple redirects, setting `enable_url_encoding` is correctly applied across all redirects in the chain. [#79563](https://github.com/ClickHouse/ClickHouse/pull/79563) ([Shankar Iyer](https://github.com/shankar-iyer)). Setting `enble_url_encoding` default value is now set to `false`. [#80088](https://github.com/ClickHouse/ClickHouse/pull/80088) ([Shankar Iyer](https://github.com/shankar-iyer)).
#### New Feature
* Support scalar correlated subqueries in the WHERE clause. Closes [#6697](https://github.com/ClickHouse/ClickHouse/issues/6697). [#79600](https://github.com/ClickHouse/ClickHouse/pull/79600) ([Dmitry Novik](https://github.com/novikd)). Support correlated subqueries in the projection list in simple cases. [#79925](https://github.com/ClickHouse/ClickHouse/pull/79925) ([Dmitry Novik](https://github.com/novikd)). [#76078](https://github.com/ClickHouse/ClickHouse/pull/76078) ([Dmitry Novik](https://github.com/novikd)). Now it covers 100% of TPC-H test suite.
* Vector search using the vector similarity index is now beta (from previously experimental). [#80164](https://github.com/ClickHouse/ClickHouse/pull/80164) ([Robert Schulze](https://github.com/rschu1ze)).
* Support geo types in `Parquet` format. This closes [#75317](https://github.com/ClickHouse/ClickHouse/issues/75317). [#79777](https://github.com/ClickHouse/ClickHouse/pull/79777) ([scanhex12](https://github.com/scanhex12)).
* New functions `sparseGrams`, `sparseGramsHashes`, `sparseGramsHashesUTF8`, `sparseGramsUTF8` for calculating "sparse-ngrams" - a robust algorithm for extracting substrings for indexing and search. [#79517](https://github.com/ClickHouse/ClickHouse/pull/79517) ([scanhex12](https://github.com/scanhex12)).
* `clickhouse-local` (and its shorthand alias, `ch`) now use an implicit `FROM table` when there is input data for processing. This closes [#65023](https://github.com/ClickHouse/ClickHouse/issues/65023). Also enabled format inference in clickhouse-local if `--input-format` is not specified and it processes a regular file. [#79085](https://github.com/ClickHouse/ClickHouse/pull/79085) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add `stringBytesUniq` and `stringBytesEntropy` functions to search for possibly random or encrypted data. [#79350](https://github.com/ClickHouse/ClickHouse/pull/79350) ([Sachin Kumar Singh](https://github.com/sachinkumarsingh092)).
* Added functions for encoding and decoding base32. [#79809](https://github.com/ClickHouse/ClickHouse/pull/79809) ([Joanna Hulboj](https://github.com/jh0x)).
* Add `getServerSetting` and `getMergeTreeSetting` function. Closes #78318. [#78439](https://github.com/ClickHouse/ClickHouse/pull/78439) ([NamNguyenHoai](https://github.com/NamHoaiNguyen)).
* Add new `iceberg_enable_version_hint` setting to leverage `version-hint.text` file. [#78594](https://github.com/ClickHouse/ClickHouse/pull/78594) ([Arnaud Briche](https://github.com/arnaudbriche)).
* Gives the possibility to truncate specific tables from a database, filtered with the `LIKE` keyword. [#78597](https://github.com/ClickHouse/ClickHouse/pull/78597) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Support `_part_starting_offset` virtual column in `MergeTree`-family tables. This column represents the cumulative row count of all preceding parts, calculated at query time based on the current part list. The cumulative values are retained throughout query execution and remain effective even after part pruning. Related internal logic has been refactored to support this behavior. [#79417](https://github.com/ClickHouse/ClickHouse/pull/79417) ([Amos Bird](https://github.com/amosbird)).
* Add functions `divideOrNull`,`moduloOrNull`, `intDivOrNull`,`positiveModuloOrNull` to return NULL when right argument is zero. [#78276](https://github.com/ClickHouse/ClickHouse/pull/78276) ([kevinyhzou](https://github.com/KevinyhZou)).
* Clickhouse vector search now supports both pre-filtering and post-filtering and provides related settings for finer control. (issue [#78161](https://github.com/ClickHouse/ClickHouse/issues/78161)). [#79854](https://github.com/ClickHouse/ClickHouse/pull/79854) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Add [`icebergHash`](https://iceberg.apache.org/spec/#appendix-b-32-bit-hash-requirements) and [`icebergBucket`](https://iceberg.apache.org/spec/#bucket-transform-details) functions. Support data files pruning in `Iceberg` tables partitioned with [`bucket transfom`](https://iceberg.apache.org/spec/#partitioning). [#79262](https://github.com/ClickHouse/ClickHouse/pull/79262) ([Daniil Ivanik](https://github.com/divanik)).
#### Experimental Feature
* New `Time`/`Time64` data types: `Time` (HHH:MM:SS) and `Time64` (HHH:MM:SS.``) and some basic cast functions and functions to interact with other data types. Also, changed the existing function's name toTime to toTimeWithFixedDate because the function toTime is required for the cast function. [#75735](https://github.com/ClickHouse/ClickHouse/pull/75735) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
72459\).
* Hive metastore catalog for Iceberg datalake. [#77677](https://github.com/ClickHouse/ClickHouse/pull/77677) ([scanhex12](https://github.com/scanhex12)).
* Indexes of type `full_text` were renamed to `gin`. This follows the more familiar terminology of PostgreSQL and other databases. Existing indexes of type `full_text` remain loadable but they will throw an exception (suggesting `gin` indexes instead) when one tries to use them in searches. [#79024](https://github.com/ClickHouse/ClickHouse/pull/79024) ([Robert Schulze](https://github.com/rschu1ze)).
#### Performance Improvement
* Change the Compact part format to save marks for each substream to be able to read individual subcolumns. Old Compact format is still supported for reads and can be enabled for writes using MergeTree setting `write_marks_for_substreams_in_compact_parts`. It's disabled by default for safer upgrades as it changes the compact parts storage. It will be enabled by default in one of the next releases. [#77940](https://github.com/ClickHouse/ClickHouse/pull/77940) ([Pavel Kruglov](https://github.com/Avogar)).
* Allow moving conditions with subcolumns to prewhere. [#79489](https://github.com/ClickHouse/ClickHouse/pull/79489) ([Pavel Kruglov](https://github.com/Avogar)).
* Speed up secondary indices by evaluating their expressions on multiple granules at once. [#64109](https://github.com/ClickHouse/ClickHouse/pull/64109) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Enable `compile_expressions` (JIT compiler for fragments of ordinary expressions) by default. This closes [#51264](https://github.com/ClickHouse/ClickHouse/issues/51264) and [#56386](https://github.com/ClickHouse/ClickHouse/issues/56386) and [#66486](https://github.com/ClickHouse/ClickHouse/issues/66486). [#79907](https://github.com/ClickHouse/ClickHouse/pull/79907) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* New setting introduced: `use_skip_indexes_in_final_exact_mode`. If a query on a `ReplacingMergeTree` table has FINAL clause, reading only table ranges based on skip indexes may produce incorrect result. This setting can ensure that correct results are returned by scanning newer parts that have overlap with primary key ranges returned by the skip index. Set to 0 to disable, 1 to enable. [#78350](https://github.com/ClickHouse/ClickHouse/pull/78350) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Object storage cluster table functions (e.g. `s3Cluster`) will now assign files to replicas for reading based on consistent hash to improve cache locality. [#77326](https://github.com/ClickHouse/ClickHouse/pull/77326) ([Andrej Hoos](https://github.com/adikus)).
* Improve performance of `S3Queue`/`AzureQueue` by allowing INSERTs data in parallel (can be enabled with `parallel_inserts=true` queue setting). Previously S3Queue/AzureQueue can only do first part of pipeline in parallel (downloading, parsing), INSERT was single-threaded. And `INSERT`s are almost always the bottleneck. Now it will scale almost linear with `processing_threads_num`. [#77671](https://github.com/ClickHouse/ClickHouse/pull/77671) ([Azat Khuzhin](https://github.com/azat)). More fair max\_processed\_files\_before\_commit in S3Queue/AzureQueue. [#79363](https://github.com/ClickHouse/ClickHouse/pull/79363) ([Azat Khuzhin](https://github.com/azat)).
* Introduced threshold (regulated by setting `parallel_hash_join_threshold`) to fall back to the `hash` algorithm when the size of the right table is below the threshold. [#76185](https://github.com/ClickHouse/ClickHouse/pull/76185) ([Nikita Taranov](https://github.com/nickitat)).
* Now we use number of replicas to determine task size for reading with parallel replicas enabled. This provides better work distribution between replicas when the amount of data to read is not really big. [#78695](https://github.com/ClickHouse/ClickHouse/pull/78695) ([Nikita Taranov](https://github.com/nickitat)).
* Allow parallel merging of `uniqExact` states during the final stage of distributed aggregation. [#78703](https://github.com/ClickHouse/ClickHouse/pull/78703) ([Nikita Taranov](https://github.com/nickitat)).
* Fix possible performance degradation of the parallel merging of `uniqExact` states for aggregation with key. [#78724](https://github.com/ClickHouse/ClickHouse/pull/78724) ([Nikita Taranov](https://github.com/nickitat)).
* Reduce the number of List Blobs API calls to Azure storage. [#78860](https://github.com/ClickHouse/ClickHouse/pull/78860) ([Julia Kartseva](https://github.com/jkartseva)).
* Fix performance of the distributed INSERT SELECT with parallel replicas. [#79441](https://github.com/ClickHouse/ClickHouse/pull/79441) ([Azat Khuzhin](https://github.com/azat)).
* Prevent `LogSeriesLimiter` from doing cleanup on every construction, avoiding lock contention and performance regressions in high-concurrency scenarios. [#79864](https://github.com/ClickHouse/ClickHouse/pull/79864) ([filimonov](https://github.com/filimonov)).
* Speedup queries with trivial count optimization. [#79945](https://github.com/ClickHouse/ClickHouse/pull/79945) ([Raúl Marín](https://github.com/Algunenano)).
* Better inlining for some operations with `Decimal`. [#79999](https://github.com/ClickHouse/ClickHouse/pull/79999) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Set `input_format_parquet_bloom_filter_push_down` to true by default. Also, fix a mistake in the settings changes history. [#80058](https://github.com/ClickHouse/ClickHouse/pull/80058) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Optimized `ALTER ... DELETE` mutations for parts in which all rows should be deleted. Now, in such cases an empty part is created instead of original without executing a mutation. [#79307](https://github.com/ClickHouse/ClickHouse/pull/79307) ([Anton Popov](https://github.com/CurtizJ)).
* Avoid extra copying of the block during insertion into Compact part when possible. [#79536](https://github.com/ClickHouse/ClickHouse/pull/79536) ([Pavel Kruglov](https://github.com/Avogar)).
* Add setting `input_format_max_block_size_bytes` to limit blocks created in input formats in bytes. It can help to avoid high memory usage during data import when rows contains large values. [#79495](https://github.com/ClickHouse/ClickHouse/pull/79495) ([Pavel Kruglov](https://github.com/Avogar)).
* Remove guard pages for threads and async\_socket\_for\_remote/use\_hedge\_requests. Change the allocation method in `FiberStack` from `mmap` to `aligned_alloc`. Since this splits VMAs and under heavy load vm.max\_map\_count can be reached. [#79147](https://github.com/ClickHouse/ClickHouse/pull/79147) ([Sema Checherinda](https://github.com/CheSema)).
* Lazy Materialization with parallel replicas. [#79401](https://github.com/ClickHouse/ClickHouse/pull/79401) ([Igor Nikonov](https://github.com/devcrafter)).
#### Improvement
* Added an ability to apply lightweight deletes on the fly (with settings `lightweight_deletes_sync = 0`, `apply_mutations_on_fly = 1`. [#79281](https://github.com/ClickHouse/ClickHouse/pull/79281) ([Anton Popov](https://github.com/CurtizJ)).
* If data in the pretty format is displayed in the terminal, and a subsequent block has the same column widths, it can continue from the previous block, glue it to the previous block by moving the cursor up. This closes [#79333](https://github.com/ClickHouse/ClickHouse/issues/79333). The feature is controlled by the new setting, `output_format_pretty_glue_chunks`. [#79339](https://github.com/ClickHouse/ClickHouse/pull/79339) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Extend the `isIPAddressInRange` function to `String`, `IPv4`, `IPv6`, `Nullable(String)`, `Nullable(IPv4)`, and `Nullable(IPv6)` data types. [#78364](https://github.com/ClickHouse/ClickHouse/pull/78364) ([YjyJeff](https://github.com/YjyJeff)).
* Allow changing `PostgreSQL` engine connection pooler settings dynamically. [#78414](https://github.com/ClickHouse/ClickHouse/pull/78414) ([Samay Sharma](https://github.com/samay-sharma)).
* Allow to specify `_part_offset` in normal projection. This is the first step to build projection index. It can be used with [#58224](https://github.com/ClickHouse/ClickHouse/issues/58224) and can help improve #63207. [#78429](https://github.com/ClickHouse/ClickHouse/pull/78429) ([Amos Bird](https://github.com/amosbird)).
* Add new columns (`create_query` and `source`) for `system.named_collections`. Closes [#78179](https://github.com/ClickHouse/ClickHouse/issues/78179). [#78582](https://github.com/ClickHouse/ClickHouse/pull/78582) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* Added a new field `condition` to system table `system.query_condition_cache`. It stores the plaintext condition whose hash is used as a key in the query condition cache. [#78671](https://github.com/ClickHouse/ClickHouse/pull/78671) ([Robert Schulze](https://github.com/rschu1ze)).
* Vector similarity indexes can now be created on top of `BFloat16` columns. [#78850](https://github.com/ClickHouse/ClickHouse/pull/78850) ([Robert Schulze](https://github.com/rschu1ze)).
* Support unix timestapms with fractional part in best effort `DateTime64` parsing. [#78908](https://github.com/ClickHouse/ClickHouse/pull/78908) ([Pavel Kruglov](https://github.com/Avogar)).
* In the storage `DeltaLake` delta-kernel implementation, fix for column mapping mode, add tests for schema evolution. [#78921](https://github.com/ClickHouse/ClickHouse/pull/78921) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Improve insert into `Variant` column in Values format by better conversion of values. [#78923](https://github.com/ClickHouse/ClickHouse/pull/78923) ([Pavel Kruglov](https://github.com/Avogar)).
* The `tokens` function was extended to accept an additional "tokenizer" argument plus further tokenizer-specific arguments. [#79001](https://github.com/ClickHouse/ClickHouse/pull/79001) ([Elmi Ahmadov](https://github.com/ahmadov)).
* The `SHOW CLUSTER` statement now expands macros (if any) in its argument. [#79006](https://github.com/ClickHouse/ClickHouse/pull/79006) ([arf42](https://github.com/arf42)).
* Hash functions now support `NULL`s inside arrays, tuples, and maps. (issues [#48365](https://github.com/ClickHouse/ClickHouse/issues/48365) and [#48623](https://github.com/ClickHouse/ClickHouse/issues/48623)). [#79008](https://github.com/ClickHouse/ClickHouse/pull/79008) ([Michael Kolupaev](https://github.com/al13n321)).
* Update cctz to 2025a. [#79043](https://github.com/ClickHouse/ClickHouse/pull/79043) ([Raúl Marín](https://github.com/Algunenano)).
* Change the default stderr processing for UDFs to "log\_last". It's better for usability. [#79066](https://github.com/ClickHouse/ClickHouse/pull/79066) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Make tabs undo-able in the Web UI. This closes [#71284](https://github.com/ClickHouse/ClickHouse/issues/71284). [#79084](https://github.com/ClickHouse/ClickHouse/pull/79084) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Remove settings during `recoverLostReplica` same as it was done in: [https://github.com/ClickHouse/ClickHouse/pull/78637](https://github.com/ClickHouse/ClickHouse/pull/78637). [#79113](https://github.com/ClickHouse/ClickHouse/pull/79113) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Add profile events: `ParquetReadRowGroups` and `ParquetPrunedRowGroups` to profile parquet index prune. [#79180](https://github.com/ClickHouse/ClickHouse/pull/79180) ([flynn](https://github.com/ucasfl)).
* Support `ALTER`ing database on cluster. [#79242](https://github.com/ClickHouse/ClickHouse/pull/79242) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Explicitly skip missed runs of statistics collection for QueryMetricLog, otherwise the log will take a long time to catch up with the current time. [#79257](https://github.com/ClickHouse/ClickHouse/pull/79257) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Some small optimizations for reading `Arrow`-based formats. [#79308](https://github.com/ClickHouse/ClickHouse/pull/79308) ([Bharat Nallan](https://github.com/bharatnc)).
* The setting `allow_archive_path_syntax` was marked as experimental by mistake. Add a test to prevent having experimental settings enabled by default. [#79320](https://github.com/ClickHouse/ClickHouse/pull/79320) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Made page cache settings adjustable on a per-query level. This is needed for faster experimentation and for the possibility of fine-tuning for high-throughput and low-latency queries. [#79337](https://github.com/ClickHouse/ClickHouse/pull/79337) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Do not print number tips in pretty formats for numbers that look like most of the 64-bit hashes. This closes [#79334](https://github.com/ClickHouse/ClickHouse/issues/79334). [#79338](https://github.com/ClickHouse/ClickHouse/pull/79338) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Colors of graphs on the advanced dashboards will be calculated from the hash of the corresponding query. This makes it easier to remember and locate a graph while scrolling the dashboard. [#79341](https://github.com/ClickHouse/ClickHouse/pull/79341) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add asynchronous metric, `FilesystemCacheCapacity` - total capacity in the `cache` virtual filesystem. This is useful for global infrastructure monitoring. [#79348](https://github.com/ClickHouse/ClickHouse/pull/79348) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Optimize access to system.parts (read columns/indexes size only when requested). [#79352](https://github.com/ClickHouse/ClickHouse/pull/79352) ([Azat Khuzhin](https://github.com/azat)).
* Calculate the relevant fields for query `'SHOW CLUSTER '` instead of all fields. [#79368](https://github.com/ClickHouse/ClickHouse/pull/79368) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Allow to specify storage settings for `DatabaseCatalog`. [#79407](https://github.com/ClickHouse/ClickHouse/pull/79407) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Support local storage in `DeltaLake`. [#79416](https://github.com/ClickHouse/ClickHouse/pull/79416) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Add a query level setting to enable delta-kernel-rs: `allow_experimental_delta_kernel_rs`. [#79418](https://github.com/ClickHouse/ClickHouse/pull/79418) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix possible endless loop when listing blobs from Azure/S3 blob storage. [#79425](https://github.com/ClickHouse/ClickHouse/pull/79425) ([Alexander Gololobov](https://github.com/davenger)).
* Add filesystem cache setting `max_size_ratio_to_total_space`. [#79460](https://github.com/ClickHouse/ClickHouse/pull/79460) ([Kseniia Sumarokova](https://github.com/kssenii)).
* For `clickhouse-benchmark` reconfigure `reconnect` option to take 0, 1 or N as values for reconnecting accordingly. [#79465](https://github.com/ClickHouse/ClickHouse/pull/79465) ([Sachin Kumar Singh](https://github.com/sachinkumarsingh092)).
* Allow `ALTER TABLE ... MOVE|REPLACE PARTITION` for tables on different `plain_rewritable` disks. [#79566](https://github.com/ClickHouse/ClickHouse/pull/79566) ([Julia Kartseva](https://github.com/jkartseva)).
* The vector similarity index is now also used if the reference vector is of type `Array(BFloat16)`. [#79745](https://github.com/ClickHouse/ClickHouse/pull/79745) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Add last\_error\_message, last\_error\_trace and query\_id to the system.error\_log table. Related ticket [#75816](https://github.com/ClickHouse/ClickHouse/issues/75816). [#79836](https://github.com/ClickHouse/ClickHouse/pull/79836) ([Andrei Tinikov](https://github.com/Dolso)).
* Enable sending crash reports by default. This can be turned off in the server's configuration file. [#79838](https://github.com/ClickHouse/ClickHouse/pull/79838) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* System table `system.functions` now shows in which ClickHouse version functions were first introduced. [#79839](https://github.com/ClickHouse/ClickHouse/pull/79839) ([Robert Schulze](https://github.com/rschu1ze)).
* Added `access_control_improvements.enable_user_name_access_type` setting. This setting allows enabling/disabling of precise grants for users/roles, introduced in [https://github.com/ClickHouse/ClickHouse/pull/72246](https://github.com/ClickHouse/ClickHouse/pull/72246). You may want to turn this setting off in case you have a cluster with the replicas older than 25.1. [#79842](https://github.com/ClickHouse/ClickHouse/pull/79842) ([pufit](https://github.com/pufit)).
* Proper implementation of `ASTSelectWithUnionQuery::clone()` method now takes into account `is_normalized` field as well. This might help with [#77569](https://github.com/ClickHouse/ClickHouse/issues/77569). [#79909](https://github.com/ClickHouse/ClickHouse/pull/79909) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Fix the inconsistent formatting of certain queries with the EXCEPT operator. If the left-hand side of the EXCEPT operator ends with `*`, the formatted query loses parentheses and is then parsed as a `*` with the `EXCEPT` modifier. These queries are found by the fuzzer and are unlikely to be found in practice. This closes [#79950](https://github.com/ClickHouse/ClickHouse/issues/79950). [#79952](https://github.com/ClickHouse/ClickHouse/pull/79952) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Small improvement in `JSON` type parsing by using cache of variants deserialization order. [#79984](https://github.com/ClickHouse/ClickHouse/pull/79984) ([Pavel Kruglov](https://github.com/Avogar)).
* Add setting `s3_slow_all_threads_after_network_error`. [#80035](https://github.com/ClickHouse/ClickHouse/pull/80035) ([Vitaly Baranov](https://github.com/vitlibar)).
* The logging level about the selected parts to merge was wrong (Information). Closes [#80061](https://github.com/ClickHouse/ClickHouse/issues/80061). [#80062](https://github.com/ClickHouse/ClickHouse/pull/80062) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* trace-visualizer: add runtime/share in tooltips and status messages. [#79040](https://github.com/ClickHouse/ClickHouse/pull/79040) ([Sergei Trifonov](https://github.com/serxa)).
* trace-visualizer: load data from clickhouse server. [#79042](https://github.com/ClickHouse/ClickHouse/pull/79042) ([Sergei Trifonov](https://github.com/serxa)).
* Add metrics on failing merges. [#79228](https://github.com/ClickHouse/ClickHouse/pull/79228) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* `clickhouse-benchmark` will display percentage based on the max iterations if specified. [#79346](https://github.com/ClickHouse/ClickHouse/pull/79346) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add system.parts table visualizer. [#79437](https://github.com/ClickHouse/ClickHouse/pull/79437) ([Sergei Trifonov](https://github.com/serxa)).
* Add tool for query latency analyzing. [#79978](https://github.com/ClickHouse/ClickHouse/pull/79978) ([Sergei Trifonov](https://github.com/serxa)).
#### Bug Fix (user-visible misbehavior in an official stable release)
* Fix renames of columns missing in part. [#76346](https://github.com/ClickHouse/ClickHouse/pull/76346) ([Anton Popov](https://github.com/CurtizJ)).
* A materialized view can start too late, e.g. after the Kafka table that streams to it. [#72123](https://github.com/ClickHouse/ClickHouse/pull/72123) ([Ilya Golshtein](https://github.com/ilejn)).
* Fix `SELECT` query rewriting during `VIEW` creation with enabled analyzer. closes [#75956](https://github.com/ClickHouse/ClickHouse/issues/75956). [#76356](https://github.com/ClickHouse/ClickHouse/pull/76356) ([Dmitry Novik](https://github.com/novikd)).
* Fix applying `async_insert` from server (via `apply_settings_from_server`) (previously leads to `Unknown packet 11 from server` errors on the client). [#77578](https://github.com/ClickHouse/ClickHouse/pull/77578) ([Azat Khuzhin](https://github.com/azat)).
* Fixed refreshable materialized view in Replicated database not working on newly added replicas. [#77774](https://github.com/ClickHouse/ClickHouse/pull/77774) ([Michael Kolupaev](https://github.com/al13n321)).
* Fixed refreshable materialized views breaking backups. [#77893](https://github.com/ClickHouse/ClickHouse/pull/77893) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix old firing logical error for `transform`. [#78247](https://github.com/ClickHouse/ClickHouse/pull/78247) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Fix some cases where secondary index was not applied with analyzer. Fixes [#65607](https://github.com/ClickHouse/ClickHouse/issues/65607) , fixes [#69373](https://github.com/ClickHouse/ClickHouse/issues/69373). [#78485](https://github.com/ClickHouse/ClickHouse/pull/78485) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fix dumping profile events (`NetworkSendElapsedMicroseconds`/`NetworkSendBytes`) for HTTP protocol with compression enabled (the error should not be more then the buffer size, usually around 1MiB). [#78516](https://github.com/ClickHouse/ClickHouse/pull/78516) ([Azat Khuzhin](https://github.com/azat)).
* Fix analyzer producing LOGICAL\_ERROR when JOIN ... USING involves ALIAS column - should produce appropriate error. [#78618](https://github.com/ClickHouse/ClickHouse/pull/78618) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Fix analyzer: CREATE VIEW ... ON CLUSTER fails if SELECT contains positional arguments. [#78663](https://github.com/ClickHouse/ClickHouse/pull/78663) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Fix `Block structure mismatch` error in case of `INSERT SELECT` into table a function with schema inference if `SELECT` has scalar subqueries. [#78677](https://github.com/ClickHouse/ClickHouse/pull/78677) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Fix analyzer: with prefer\_global\_in\_and\_join=1 for Distributed table in SELECT query `in` function should be replaced by `globalIn`. [#78749](https://github.com/ClickHouse/ClickHouse/pull/78749) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Fixed several types of `SELECT` queries that read from tables with `MongoDB` engine or `mongodb` table function: queries with implicit conversion of const value in `WHERE` clause (e.g. `WHERE datetime = '2025-03-10 00:00:00'`) ; queries with `LIMIT` and `GROUP BY`. Previously, they could return the wrong result. [#78777](https://github.com/ClickHouse/ClickHouse/pull/78777) ([Anton Popov](https://github.com/CurtizJ)).
* Fix conversion between different JSON types. Not it's performed by simple cast through convertion to/from String. It's less effective but 100% accurate. [#78807](https://github.com/ClickHouse/ClickHouse/pull/78807) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix logical error during convertion of Dynamic type to Interval. [#78813](https://github.com/ClickHouse/ClickHouse/pull/78813) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix column rollback on JSON parsing error. [#78836](https://github.com/ClickHouse/ClickHouse/pull/78836) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix 'bad cast' error when join using constant alias column. [#78848](https://github.com/ClickHouse/ClickHouse/pull/78848) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Don't allow prewhere in materialized view on columns with different types in view and target table. [#78889](https://github.com/ClickHouse/ClickHouse/pull/78889) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix logical error during parsing of bad binary data of Variant column. [#78982](https://github.com/ClickHouse/ClickHouse/pull/78982) ([Pavel Kruglov](https://github.com/Avogar)).
* Throw an exception when the parquet batch size is set to 0. Previously when output\_format\_parquet\_batch\_size = 0 ClickHouse would hang. Now this behavior is fixed. [#78991](https://github.com/ClickHouse/ClickHouse/pull/78991) ([daryawessely](https://github.com/daryawessely)).
* Fix deserialization of variant discriminators with basic format in compact parts. It was introduced in [https://github.com/ClickHouse/ClickHouse/pull/55518](https://github.com/ClickHouse/ClickHouse/pull/55518). [#79000](https://github.com/ClickHouse/ClickHouse/pull/79000) ([Pavel Kruglov](https://github.com/Avogar)).
* Dictionaries of type `complex_key_ssd_cache` now reject zero or negative `block_size` and `write_buffer_size` parameters (issue [#78314](https://github.com/ClickHouse/ClickHouse/issues/78314)). [#79028](https://github.com/ClickHouse/ClickHouse/pull/79028) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Avoid using Field for non-aggregated columns in SummingMergeTree. It could lead to unexpected errors with Dynamic/Variant types used in SummingMergeTree. [#79051](https://github.com/ClickHouse/ClickHouse/pull/79051) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix read from Materialized View with Distributed destination table and different header in analyzer. [#79059](https://github.com/ClickHouse/ClickHouse/pull/79059) ([Pavel Kruglov](https://github.com/Avogar)).
* Fixes a bug where `arrayUnion()` returned extra (incorrect) values on tables that had batch inserts. Fixes [#75057](https://github.com/ClickHouse/ClickHouse/issues/75057). [#79079](https://github.com/ClickHouse/ClickHouse/pull/79079) ([Peter Nguyen](https://github.com/petern48)).
* Fix segfault in `OpenSSLInitializer`. Closes [#79092](https://github.com/ClickHouse/ClickHouse/issues/79092). [#79097](https://github.com/ClickHouse/ClickHouse/pull/79097) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Always set prefix for S3 ListObject. [#79114](https://github.com/ClickHouse/ClickHouse/pull/79114) ([Azat Khuzhin](https://github.com/azat)).
* Fixes a bug where arrayUnion() returned extra (incorrect) values on tables that had batch inserts. Fixes [#79157](https://github.com/ClickHouse/ClickHouse/issues/79157). [#79158](https://github.com/ClickHouse/ClickHouse/pull/79158) ([Peter Nguyen](https://github.com/petern48)).
* Fix logical error after filter pushdown. [#79164](https://github.com/ClickHouse/ClickHouse/pull/79164) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Fix DeltaLake table engine with delta-kernel implementation being used with http based endpoints, fix NOSIGN. Closes [#78124](https://github.com/ClickHouse/ClickHouse/issues/78124). [#79203](https://github.com/ClickHouse/ClickHouse/pull/79203) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Keeper fix: Avoid triggering watches on failed multi requests. [#79247](https://github.com/ClickHouse/ClickHouse/pull/79247) ([Antonio Andelic](https://github.com/antonio2368)).
* Forbid Dynamic and JSON types in IN. With current implementation of `IN` it can lead to incorrect results. Proper support of this types in `IN` is complicated and can be done in future. [#79282](https://github.com/ClickHouse/ClickHouse/pull/79282) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix check for duplicate paths in JSON type parsing. [#79317](https://github.com/ClickHouse/ClickHouse/pull/79317) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix SecureStreamSocket connection issues. [#79383](https://github.com/ClickHouse/ClickHouse/pull/79383) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fix loading of plain\_rewritable disks containing data. [#79439](https://github.com/ClickHouse/ClickHouse/pull/79439) ([Julia Kartseva](https://github.com/jkartseva)).
* Fix crash in dynamic subcolumns discovery in Wide parts in MergeTree. [#79466](https://github.com/ClickHouse/ClickHouse/pull/79466) ([Pavel Kruglov](https://github.com/Avogar)).
* Verify the table name's length only for initial create queries. Do not verify this for secondary creates to avoid backward compatibility issues. [#79488](https://github.com/ClickHouse/ClickHouse/pull/79488) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Fixed error `Block structure mismatch` in several cases with tables with sparse columns. [#79491](https://github.com/ClickHouse/ClickHouse/pull/79491) ([Anton Popov](https://github.com/CurtizJ)).
* Fix two cases of "Logical Error: Can't set alias of \* of Asterisk on alias". [#79505](https://github.com/ClickHouse/ClickHouse/pull/79505) ([Raúl Marín](https://github.com/Algunenano)).
* Fix using incorrect paths when renaming an Atomic database. [#79569](https://github.com/ClickHouse/ClickHouse/pull/79569) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Fix order by JSON column with other columns. [#79591](https://github.com/ClickHouse/ClickHouse/pull/79591) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix result duplication when reading from remote with both `use_hedged_requests` and `allow_experimental_parallel_reading_from_replicas` disabled. [#79599](https://github.com/ClickHouse/ClickHouse/pull/79599) ([Eduard Karacharov](https://github.com/korowa)).
* Fix crash in delta-kernel implementation when using unity catalog. [#79677](https://github.com/ClickHouse/ClickHouse/pull/79677) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Resolve macros for autodiscovery clusters. [#79696](https://github.com/ClickHouse/ClickHouse/pull/79696) ([Anton Ivashkin](https://github.com/ianton-ru)).
* Handle incorrectly configured page\_cache\_limits suitably. [#79805](https://github.com/ClickHouse/ClickHouse/pull/79805) ([Bharat Nallan](https://github.com/bharatnc)).
* Fixes the result of SQL function `formatDateTime` if a variable-size formatter (e.g. `%W` aka. weekday `Monday` `Tuesday`, etc.) is followed by a compound formatter (a formatter that prints multiple components at once, e.g. `%D` aka. the American date `05/04/25`). [#79835](https://github.com/ClickHouse/ClickHouse/pull/79835) ([Robert Schulze](https://github.com/rschu1ze)).
* IcebergS3 supports count optimization, but IcebergS3Cluster does not. As a result, the count() result returned in cluster mode may be a multiple of the number of replicas. [#79844](https://github.com/ClickHouse/ClickHouse/pull/79844) ([wxybear](https://github.com/wxybear)).
* Fixes AMBIGUOUS\_COLUMN\_NAME error with lazy materialization when no columns are used for query execution until projection. Example, SELECT \* FROM t ORDER BY rand() LIMIT 5. [#79926](https://github.com/ClickHouse/ClickHouse/pull/79926) ([Igor Nikonov](https://github.com/devcrafter)).
* Hide password for query `CREATE DATABASE datalake ENGINE = DataLakeCatalog(\'http://catalog:8181\', \'admin\', \'password\')`. [#79941](https://github.com/ClickHouse/ClickHouse/pull/79941) ([Han Fei](https://github.com/hanfei1991)).
* Allow to specify an alias in JOIN USING. Specify this alias in case the column was renamed (e.g., because of ARRAY JOIN). Fixes [#73707](https://github.com/ClickHouse/ClickHouse/issues/73707). [#79942](https://github.com/ClickHouse/ClickHouse/pull/79942) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Allow materialized views with UNIONs to work correctly on new replicas. [#80037](https://github.com/ClickHouse/ClickHouse/pull/80037) ([Samay Sharma](https://github.com/samay-sharma)).
* Format specifier `%e` in SQL function `parseDateTime` now recognizes single-digit days (e.g. `3`), whereas it previously required space padding (e.g. ` 3`). This makes its behavior compatible with MySQL. To retain the previous behaviour, set setting `parsedatetime_e_requires_space_padding = 1`. (issue [#78243](https://github.com/ClickHouse/ClickHouse/issues/78243)). [#80057](https://github.com/ClickHouse/ClickHouse/pull/80057) ([Robert Schulze](https://github.com/rschu1ze)).
* Fix warnings `Cannot find 'kernel' in '[...]/memory.stat'` in ClickHouse's log (issue [#77410](https://github.com/ClickHouse/ClickHouse/issues/77410)). [#80129](https://github.com/ClickHouse/ClickHouse/pull/80129) ([Robert Schulze](https://github.com/rschu1ze)).
* Check stack size in FunctionComparison to avoid stack overflow crash. [#78208](https://github.com/ClickHouse/ClickHouse/pull/78208) ([Julia Kartseva](https://github.com/jkartseva)).
* Fix race during SELECT from `system.workloads`. [#78743](https://github.com/ClickHouse/ClickHouse/pull/78743) ([Sergei Trifonov](https://github.com/serxa)).
* Fix: lazy materialization in distributed queries. [#78815](https://github.com/ClickHouse/ClickHouse/pull/78815) ([Igor Nikonov](https://github.com/devcrafter)).
* Fix `Array(Bool)` to `Array(FixedString)` conversion. [#78863](https://github.com/ClickHouse/ClickHouse/pull/78863) ([Nikita Taranov](https://github.com/nickitat)).
* Make parquet version selection less confusing. [#78818](https://github.com/ClickHouse/ClickHouse/pull/78818) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix `ReservoirSampler` self-merging. [#79031](https://github.com/ClickHouse/ClickHouse/pull/79031) ([Nikita Taranov](https://github.com/nickitat)).
* Fix storage of insertion table in client context. [#79046](https://github.com/ClickHouse/ClickHouse/pull/79046) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Fix the destruction order of data members of `AggregatingSortedAlgorithm` and `SummingSortedAlgorithm`. [#79056](https://github.com/ClickHouse/ClickHouse/pull/79056) ([Nikita Taranov](https://github.com/nickitat)).
* `enable_user_name_access_type` must not affect `DEFINER` access type. [#80026](https://github.com/ClickHouse/ClickHouse/pull/80026) ([pufit](https://github.com/pufit)).
* Query to system database can hang if system database metadata located in keeper. [#79304](https://github.com/ClickHouse/ClickHouse/pull/79304) ([Mikhail Artemenko](https://github.com/Michicosun)).
#### Build/Testing/Packaging Improvement
* Make it possible to reuse the built `chcache` binary instead of always rebuilding it. [#78851](https://github.com/ClickHouse/ClickHouse/pull/78851) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Add NATS pause waiting. [#78987](https://github.com/ClickHouse/ClickHouse/pull/78987) ([Dmitry Novikov](https://github.com/dmitry-sles-novikov)).
* Fix for incorrectly publishing ARM build as amd64compat. [#79122](https://github.com/ClickHouse/ClickHouse/pull/79122) ([Alexander Gololobov](https://github.com/davenger)).
* Use generated ahead of time assembly for OpenSSL. [#79386](https://github.com/ClickHouse/ClickHouse/pull/79386) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fixes to allow building with `clang20`. [#79588](https://github.com/ClickHouse/ClickHouse/pull/79588) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* `chcache`: Rust caching support. [#78691](https://github.com/ClickHouse/ClickHouse/pull/78691) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Add unwind information for `zstd` assembly files. [#79288](https://github.com/ClickHouse/ClickHouse/pull/79288) ([Michael Kolupaev](https://github.com/al13n321)).
ClickHouse release 25.4, 2025-04-22
#### Backward Incompatible Change
* Check if all columns in a materialized view match the target table when `allow_materialized_view_with_bad_select` is `false`. [#74481](https://github.com/ClickHouse/ClickHouse/pull/74481) ([Christoph Wurm](https://github.com/cwurm)).
* Fix cases where `dateTrunc` is used with negative Date/DateTime arguments. [#77622](https://github.com/ClickHouse/ClickHouse/pull/77622) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* The legacy `MongoDB` integration has been removed. Server setting `use_legacy_mongodb_integration` became obsolete and now does nothing. [#77895](https://github.com/ClickHouse/ClickHouse/pull/77895) ([Robert Schulze](https://github.com/rschu1ze)).
* Enhance `SummingMergeTree` validation to skip aggregation for columns used in partition or sort keys. [#78022](https://github.com/ClickHouse/ClickHouse/pull/78022) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
#### New Feature
* Added CPU slot scheduling for workloads, see [the docs](/concepts/features/configuration/server-config/workload-scheduling#cpu_scheduling) for details. [#77595](https://github.com/ClickHouse/ClickHouse/pull/77595) ([Sergei Trifonov](https://github.com/serxa)).
* `clickhouse-local` will retain its databases after restart if you specify the `--path` command line argument. This closes [#50647](https://github.com/ClickHouse/ClickHouse/issues/50647). This closes [#49947](https://github.com/ClickHouse/ClickHouse/issues/49947). [#71722](https://github.com/ClickHouse/ClickHouse/pull/71722) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Reject queries when the server is overloaded. The decision is made based on the ratio of wait time (`OSCPUWaitMicroseconds`) to busy time (`OSCPUVirtualTimeMicroseconds`). The query is dropped with some probability, when this ratio is between `min_os_cpu_wait_time_ratio_to_throw` and `max_os_cpu_wait_time_ratio_to_throw` (those are query level settings). [#63206](https://github.com/ClickHouse/ClickHouse/pull/63206) ([Alexey Katsman](https://github.com/alexkats)).
* Time travel in `Iceberg`: add setting to query `Iceberg` tables as of a specific timestamp. [#71072](https://github.com/ClickHouse/ClickHouse/pull/71072) ([Brett Hoerner](https://github.com/bretthoerner)). [#77439](https://github.com/ClickHouse/ClickHouse/pull/77439) ([Daniil Ivanik](https://github.com/divanik)).
* An in-memory cache for `Iceberg` metadata, which stores manifest files/list and `metadata.json` to speed up queries. [#77156](https://github.com/ClickHouse/ClickHouse/pull/77156) ([Han Fei](https://github.com/hanfei1991)).
* Support `DeltaLake` table engine for Azure Blob Storage. Fixes [#68043](https://github.com/ClickHouse/ClickHouse/issues/68043). [#74541](https://github.com/ClickHouse/ClickHouse/pull/74541) ([Smita Kulkarni](https://github.com/SmitaRKulkarni)).
* Added an in-memory cache for deserialized vector similarity indexes. This should make repeated approximate nearest neighbor (ANN) search queries faster. The size of the new cache is controlled by server settings `vector_similarity_index_cache_size` and `vector_similarity_index_cache_max_entries`. This feature supersedes the skipping index cache feature of earlier releases. [#77905](https://github.com/ClickHouse/ClickHouse/pull/77905) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Support partition pruning in DeltaLake. [#78486](https://github.com/ClickHouse/ClickHouse/pull/78486) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Support for a background refresh in readonly `MergeTree` tables which allows querying updateable tables with an infinite amount of distributed readers (ClickHouse-native data lake). [#76467](https://github.com/ClickHouse/ClickHouse/pull/76467) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Support using custom disks to store databases metadata files. Currently it can be configured only on a global server level. [#77365](https://github.com/ClickHouse/ClickHouse/pull/77365) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Support ALTER TABLE ... ATTACH|DETACH|MOVE|REPLACE PARTITION for the plain\_rewritable disk. [#77406](https://github.com/ClickHouse/ClickHouse/pull/77406) ([Julia Kartseva](https://github.com/jkartseva)).
* Add table settings for `SASL` configuration and credentials to the `Kafka` table engine. This allows configuring SASL-based authentication to Kafka and Kafka-compatible systems directly in the CREATE TABLE statement rather than having to use configuration files or named collections. [#78810](https://github.com/ClickHouse/ClickHouse/pull/78810) ([Christoph Wurm](https://github.com/cwurm)).
* Allow setting `default_compression_codec` for MergeTree tables: it is used when the CREATE query does not explicitly define one for the given columns. This closes [#42005](https://github.com/ClickHouse/ClickHouse/issues/42005). [#66394](https://github.com/ClickHouse/ClickHouse/pull/66394) ([gvoelfin](https://github.com/gvoelfin)).
* Add `bind_host` setting in the clusters configuration so that ClickHouse can use a specific network for distributed connections. [#74741](https://github.com/ClickHouse/ClickHouse/pull/74741) ([Todd Yocum](https://github.com/toddyocum)).
* Introduce a new column, `parametrized_view_parameters` in `system.tables`. Closes [https://github.com/clickhouse/clickhouse/issues/66756](https://github.com/clickhouse/clickhouse/issues/66756). [#75112](https://github.com/ClickHouse/ClickHouse/pull/75112) ([NamNguyenHoai](https://github.com/NamHoaiNguyen)).
* Allow changing a database comment. Closes [#73351](https://github.com/ClickHouse/ClickHouse/issues/73351) ### Documentation entry for user-facing changes. [#75622](https://github.com/ClickHouse/ClickHouse/pull/75622) ([NamNguyenHoai](https://github.com/NamHoaiNguyen)).
* Support `SCRAM-SHA-256` authentication in the PostgreSQL compatibility protocol. [#76839](https://github.com/ClickHouse/ClickHouse/pull/76839) ([scanhex12](https://github.com/scanhex12)).
* Add functions `arrayLevenshteinDistance`, `arrayLevenshteinDistanceWeighted`, and `arraySimilarity`. [#77187](https://github.com/ClickHouse/ClickHouse/pull/77187) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
* The setting `parallel_distributed_insert_select` makes effect for `INSERT SELECT` into `ReplicatedMergeTree` (previously it required Distribued tables). [#78041](https://github.com/ClickHouse/ClickHouse/pull/78041) ([Igor Nikonov](https://github.com/devcrafter)).
* Introduce `toInterval` function. This function accepts 2 arguments (value and unit), and converts the value to a specific `Interval` type. [#78723](https://github.com/ClickHouse/ClickHouse/pull/78723) ([Andrew Davis](https://github.com/pulpdrew)).
* Add several convenient ways to resolve root `metadata.json` file in an iceberg table function and engine. Closes [#78455](https://github.com/ClickHouse/ClickHouse/issues/78455). [#78475](https://github.com/ClickHouse/ClickHouse/pull/78475) ([Daniil Ivanik](https://github.com/divanik)).
* Support password based auth in SSH protocol in ClickHouse. [#78586](https://github.com/ClickHouse/ClickHouse/pull/78586) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
#### Experimental Feature
* Support correlated subqueries as an argument of `EXISTS` expression in the `WHERE` clause. Closes [#72459](https://github.com/ClickHouse/ClickHouse/issues/72459). [#76078](https://github.com/ClickHouse/ClickHouse/pull/76078) ([Dmitry Novik](https://github.com/novikd)).
* Functions `sparseGrams` and `sparseGramsHashes` with ASCII and UTF8 versions added. Author: [scanhex12](https://github.com/scanhex12). [#78176](https://github.com/ClickHouse/ClickHouse/pull/78176) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)). Do not use it: the implementation will change in the next versions.
#### Performance Improvement
* Optimize performance with lazy columns, that read the data after ORDER BY and LIMIT. [#55518](https://github.com/ClickHouse/ClickHouse/pull/55518) ([Xiaozhe Yu](https://github.com/wudidapaopao)).
* Enabled the query condition cache by default. [#79080](https://github.com/ClickHouse/ClickHouse/pull/79080) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Speed-up building JOIN result by de-virtualizing calls to `col->insertFrom()`. [#77350](https://github.com/ClickHouse/ClickHouse/pull/77350) ([Alexander Gololobov](https://github.com/davenger)).
* Merge equality conditions from filter query plan step into JOIN condition if possible to allow using them as hash table keys. [#78877](https://github.com/ClickHouse/ClickHouse/pull/78877) ([Dmitry Novik](https://github.com/novikd)).
* Use dynamic sharding for JOIN if the JOIN key is a prefix of PK for both parts. This optimization is enabled with `query_plan_join_shard_by_pk_ranges` setting (disabled by default). [#74733](https://github.com/ClickHouse/ClickHouse/pull/74733) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Support `Iceberg` data pruning based on lower and upper boundary values for columns. Fixes [#77638](https://github.com/ClickHouse/ClickHouse/issues/77638). [#78242](https://github.com/ClickHouse/ClickHouse/pull/78242) ([alesapin](https://github.com/alesapin)).
* Implement trivial count optimization for `Iceberg`. Now queries with `count()` and without any filters should be faster. Closes [#77639](https://github.com/ClickHouse/ClickHouse/issues/77639). [#78090](https://github.com/ClickHouse/ClickHouse/pull/78090) ([alesapin](https://github.com/alesapin)).
* Add ability to configure the number of columns that merges can flush in parallel using `max_merge_delayed_streams_for_parallel_write` (this should reduce memory usage for vertical merges to S3 about 25x times). [#77922](https://github.com/ClickHouse/ClickHouse/pull/77922) ([Azat Khuzhin](https://github.com/azat)).
* Disable `filesystem_cache_prefer_bigger_buffer_size` when the cache is used passively, such as for merges. This lowers memory consumption on merges. [#77898](https://github.com/ClickHouse/ClickHouse/pull/77898) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Now we use number of replicas to determine task size for reading with parallel replicas enabled. This provides better work distribution between replicas when the amount of data to read is not really big. [#78695](https://github.com/ClickHouse/ClickHouse/pull/78695) ([Nikita Taranov](https://github.com/nickitat)).
* Support asynchronous IO prefetch for the `ORC` format, which improves overall performance by hiding remote IO latency. [#70534](https://github.com/ClickHouse/ClickHouse/pull/70534) ([李扬](https://github.com/taiyang-li)).
* Preallocate memory used by asynchronous inserts to improve performance. [#74945](https://github.com/ClickHouse/ClickHouse/pull/74945) ([Ilya Golshtein](https://github.com/ilejn)).
* Decrease the amount of Keeper requests by eliminating the use of single `get` requests, which could have caused a significant load on Keeper with the increased number of replicas, in places where `multiRead` is available. [#56862](https://github.com/ClickHouse/ClickHouse/pull/56862) ([Nikolay Degterinsky](https://github.com/evillique)).
* A marginal optimization for running functions on Nullable arguments. [#76489](https://github.com/ClickHouse/ClickHouse/pull/76489) ([李扬](https://github.com/taiyang-li)).
* Optimize `arraySort`. [#76850](https://github.com/ClickHouse/ClickHouse/pull/76850) ([李扬](https://github.com/taiyang-li)).
* Merge marks of the same part and write them to the query condition cache at one time to reduce the consumption of locks. [#77377](https://github.com/ClickHouse/ClickHouse/pull/77377) ([zhongyuankai](https://github.com/zhongyuankai)).
* Optimize `s3Cluster` performance for queries with one bracket expansion. [#77686](https://github.com/ClickHouse/ClickHouse/pull/77686) ([Tomáš Hromada](https://github.com/gyfis)).
* Optimize order by single Nullable or LowCardinality columns. [#77789](https://github.com/ClickHouse/ClickHouse/pull/77789) ([李扬](https://github.com/taiyang-li)).
* Optimize memory usage of the `Native` format. [#78442](https://github.com/ClickHouse/ClickHouse/pull/78442) ([Azat Khuzhin](https://github.com/azat)).
* Trivial optimization: do not rewrite `count(if(...))` to `countIf` if a type cast is required. Close [#78564](https://github.com/ClickHouse/ClickHouse/issues/78564). [#78565](https://github.com/ClickHouse/ClickHouse/pull/78565) ([李扬](https://github.com/taiyang-li)).
* The `hasAll` function can now take advantage of the `tokenbf_v1`, `ngrambf_v1` full-text skipping indices. [#77662](https://github.com/ClickHouse/ClickHouse/pull/77662) ([UnamedRus](https://github.com/UnamedRus)).
* Vector similarity index could over-allocate main memory by up to 2x. This fix reworks the memory allocation strategy, reducing the memory consumption and improving the effectiveness of the vector similarity index cache. (issue [#78056](https://github.com/ClickHouse/ClickHouse/issues/78056)). [#78394](https://github.com/ClickHouse/ClickHouse/pull/78394) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Introduce a setting `schema_type` for `system.metric_log` table with schema type. There are three allowed schemas: `wide` -- current schema, each metric/event in a separate column (most effective for reads of separate columns), `transposed` -- similar to `system.asynchronous_metric_log`, metrics/events are stored as rows, and the most interesting `transposed_with_wide_view` -- create underlying table with `transposed` schema, but also introduce a view with `wide` schema which translates queries to underlying table. In `transposed_with_wide_view` subsecond resolution for view is not supported, `event_time_microseconds` is just an alias for backward compatibility. [#78412](https://github.com/ClickHouse/ClickHouse/pull/78412) ([alesapin](https://github.com/alesapin)).
#### Improvement
* Serialize query plan for `Distributed` queries. A new setting `serialize_query_plan` is added. When enabled, queries from `Distributed` table will use a serialized query plan for remote query execution. This introduces a new packet type to TCP protocol, `true` should be added to the server config to allow processing this packet. [#69652](https://github.com/ClickHouse/ClickHouse/pull/69652) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Support `JSON` type and subcolumns reading from views. [#76903](https://github.com/ClickHouse/ClickHouse/pull/76903) ([Pavel Kruglov](https://github.com/Avogar)).
* Support ALTER DATABASE ... ON CLUSTER. [#79242](https://github.com/ClickHouse/ClickHouse/pull/79242) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Refreshes of refreshable materialized views now appear in `system.query_log`. [#71333](https://github.com/ClickHouse/ClickHouse/pull/71333) ([Michael Kolupaev](https://github.com/al13n321)).
* User-defined functions (UDFs) can now be marked as deterministic via a new setting in their configuration. Also, the query cache now checks if UDFs called within a query are deterministic. If this is the case, it caches the query result. (Issue [#59988](https://github.com/ClickHouse/ClickHouse/issues/59988)). [#77769](https://github.com/ClickHouse/ClickHouse/pull/77769) ([Jimmy Aguilar Mena](https://github.com/Ergus)).
* Enabled a backoff logic for all types of replicated tasks. It will provide the ability to reduce CPU usage, memory usage, and log file sizes. Added new settings `max_postpone_time_for_failed_replicated_fetches_ms`, `max_postpone_time_for_failed_replicated_merges_ms` and `max_postpone_time_for_failed_replicated_tasks_ms` which are similar to `max_postpone_time_for_failed_mutations_ms`. [#74576](https://github.com/ClickHouse/ClickHouse/pull/74576) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* Add `query_id` to `system.errors`. Closes [#75815](https://github.com/ClickHouse/ClickHouse/issues/75815). [#76581](https://github.com/ClickHouse/ClickHouse/pull/76581) ([Vladimir Baikov](https://github.com/bkvvldmr)).
* Adding support for converting `UInt128` to `IPv6`. This allows the `bitAnd` operation and arithmatics for `IPv6` and conversion back to `IPv6`. Closes [#76752](https://github.com/ClickHouse/ClickHouse/issues/76752). This allows the result from `bitAnd` operation on `IPv6` to be converted back to `IPv6`, as well. See also [#57707](https://github.com/ClickHouse/ClickHouse/pull/57707). [#76928](https://github.com/ClickHouse/ClickHouse/pull/76928) ([Muzammil Abdul Rehman](https://github.com/muzammilar)).
* Don't parse special `Bool` values in text formats inside `Variant` type by default. It can be enabled using setting `allow_special_bool_values_inside_variant`. [#76974](https://github.com/ClickHouse/ClickHouse/pull/76974) ([Pavel Kruglov](https://github.com/Avogar)).
* Support configurable per task waiting time of low `priority` query in session level and in server level. [#77013](https://github.com/ClickHouse/ClickHouse/pull/77013) ([VicoWu](https://github.com/VicoWu)).
* Implement comparison for values of JSON data type. Now JSON objects can be compared similarly to Maps. [#77397](https://github.com/ClickHouse/ClickHouse/pull/77397) ([Pavel Kruglov](https://github.com/Avogar)).
* Better permission support by `system.kafka_consumers`. Forward internal `librdkafka` errors (worth noting that this library is a crap). [#77700](https://github.com/ClickHouse/ClickHouse/pull/77700) ([Ilya Golshtein](https://github.com/ilejn)).
* Added validation for the settings of the Buffer table engine. [#77840](https://github.com/ClickHouse/ClickHouse/pull/77840) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* Add config `enable_hdfs_pread` to enable or disable pread in `HDFS`. [#77885](https://github.com/ClickHouse/ClickHouse/pull/77885) ([kevinyhzou](https://github.com/KevinyhZou)).
* Add profile events for number of zookeeper `multi` read and write requests. [#77888](https://github.com/ClickHouse/ClickHouse/pull/77888) ([JackyWoo](https://github.com/JackyWoo)).
* Allow creating and inserting into temporary tables when `disable_insertion_and_mutation` is on. [#77901](https://github.com/ClickHouse/ClickHouse/pull/77901) ([Xu Jia](https://github.com/XuJia0210)).
* Decrease `max_insert_delayed_streams_for_parallel_write` (to 100). [#77919](https://github.com/ClickHouse/ClickHouse/pull/77919) ([Azat Khuzhin](https://github.com/azat)).
* Fix year parsing in Joda syntax (this is from the Java world if you're wondering) like `yyy`. [#77973](https://github.com/ClickHouse/ClickHouse/pull/77973) ([李扬](https://github.com/taiyang-li)).
* Attaching parts of `MergeTree` tables will be performed in their block order, which is important for special merging algorithms, such as `ReplacingMergeTree`. This closes [#71009](https://github.com/ClickHouse/ClickHouse/issues/71009). [#77976](https://github.com/ClickHouse/ClickHouse/pull/77976) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Query masking rules are now able to throw a `LOGICAL_ERROR` in case if the match happened. This will help to check if pre-defined password is leaking anywhere in logs. [#78094](https://github.com/ClickHouse/ClickHouse/pull/78094) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Added column `index_length_column` to `information_schema.tables` for better compatibility with MySQL. [#78119](https://github.com/ClickHouse/ClickHouse/pull/78119) ([Paweł Zakrzewski](https://github.com/KrzaQ)).
* Introduce two new metrics: `TotalMergeFailures` and `NonAbortedMergeFailures`. These metrics are needed to detect the cases where too many merges fail within a short period. [#78150](https://github.com/ClickHouse/ClickHouse/pull/78150) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Fix incorrect S3 URL parsing when key is not specified on path style. [#78185](https://github.com/ClickHouse/ClickHouse/pull/78185) ([Arthur Passos](https://github.com/arthurpassos)).
* Fix incorrect values of `BlockActiveTime`, `BlockDiscardTime`, `BlockWriteTime`, `BlockQueueTime`, and `BlockReadTime` asynchronous metrics (before the change 1 second was incorrectly reported as 0.001). [#78211](https://github.com/ClickHouse/ClickHouse/pull/78211) ([filimonov](https://github.com/filimonov)).
* Respect `loading_retries` limit for errors during push to materialized view for StorageS3(Azure)Queue. Before that such errors were retried indefinitely. [#78313](https://github.com/ClickHouse/ClickHouse/pull/78313) ([Kseniia Sumarokova](https://github.com/kssenii)).
* In DeltaLake with `delta-kernel-rs` implementation, fix performance and progress bar. [#78368](https://github.com/ClickHouse/ClickHouse/pull/78368) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Support `include`, `from_env`, `from_zk` for runtime disks. Closes [#78177](https://github.com/ClickHouse/ClickHouse/issues/78177). [#78470](https://github.com/ClickHouse/ClickHouse/pull/78470) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Add a dynamic warning to the `system.warnings` table for long running mutations. [#78658](https://github.com/ClickHouse/ClickHouse/pull/78658) ([Bharat Nallan](https://github.com/bharatnc)).
* Added field `condition` to system table `system.query_condition_cache`. It stores the plaintext condition whose hash is used as a key in the query condition cache. [#78671](https://github.com/ClickHouse/ClickHouse/pull/78671) ([Robert Schulze](https://github.com/rschu1ze)).
* Allow an empty value for Hive partitioning. [#78816](https://github.com/ClickHouse/ClickHouse/pull/78816) ([Arthur Passos](https://github.com/arthurpassos)).
* Fix `IN` clause type coercion for `BFloat16` (i.e. `SELECT toBFloat16(1) IN [1, 2, 3];` now returns `1`). Closes [#78754](https://github.com/ClickHouse/ClickHouse/issues/78754). [#78839](https://github.com/ClickHouse/ClickHouse/pull/78839) ([Raufs Dunamalijevs](https://github.com/rienath)).
* Do not check parts on other disks for `MergeTree` if `disk = ...` is set. [#78855](https://github.com/ClickHouse/ClickHouse/pull/78855) ([Azat Khuzhin](https://github.com/azat)).
* Make data types in `used_data_type_families` in `system.query_log` to be recorded with canonical names. [#78972](https://github.com/ClickHouse/ClickHouse/pull/78972) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Cleanup settings during `recoverLostReplica` same as it was done in: [#78637](https://github.com/ClickHouse/ClickHouse/pull/78637). [#79113](https://github.com/ClickHouse/ClickHouse/pull/79113) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Use insertion columns for INFILE schema inference. [#78490](https://github.com/ClickHouse/ClickHouse/pull/78490) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
#### Bug Fix (user-visible misbehavior in an official stable release)
* Fix incorrect projection analysis when `count(Nullable)` is used in aggregate projections. This fixes [#74495](https://github.com/ClickHouse/ClickHouse/issues/74495) . This PR also adds some logs around projection analysis to clarify why a projection is used or why not. [#74498](https://github.com/ClickHouse/ClickHouse/pull/74498) ([Amos Bird](https://github.com/amosbird)).
* Fix `Part <...> does not contain in snapshot of previous virtual parts. (PART_IS_TEMPORARILY_LOCKED)` during `DETACH PART`. [#76039](https://github.com/ClickHouse/ClickHouse/pull/76039) ([Aleksei Filatov](https://github.com/aalexfvk)).
* Fix not working skip indexes with expression with literals in analyzer and remove trivial casts during indexes analysis. [#77229](https://github.com/ClickHouse/ClickHouse/pull/77229) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix a bug when `close_session` query parameter didn't have any effect leading to named sessions being closed only after `session_timeout`. [#77336](https://github.com/ClickHouse/ClickHouse/pull/77336) ([Alexey Katsman](https://github.com/alexkats)).
* Fixed receiving messages from NATS server without attached Materialized Views. [#77392](https://github.com/ClickHouse/ClickHouse/pull/77392) ([Dmitry Novikov](https://github.com/dmitry-sles-novikov)).
* Fix logical error while reading from empty `FileLog` via `merge` table function, close [#75575](https://github.com/ClickHouse/ClickHouse/issues/75575). [#77441](https://github.com/ClickHouse/ClickHouse/pull/77441) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Use default format settings in `Dynamic` serialization from shared variant. [#77572](https://github.com/ClickHouse/ClickHouse/pull/77572) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix checking if the table data path exists on the local disk. [#77608](https://github.com/ClickHouse/ClickHouse/pull/77608) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Fix sending constant values to remote for some types. [#77634](https://github.com/ClickHouse/ClickHouse/pull/77634) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix a crash because of expired context in S3/AzureQueue. [#77720](https://github.com/ClickHouse/ClickHouse/pull/77720) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Hide credentials in RabbitMQ, Nats, Redis, AzureQueue table engines. [#77755](https://github.com/ClickHouse/ClickHouse/pull/77755) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix undefined behaviour on `NaN` comparison in `argMin`/`argMax`. [#77756](https://github.com/ClickHouse/ClickHouse/pull/77756) ([Raúl Marín](https://github.com/Algunenano)).
* Regularly check if merges and mutations were cancelled even in case when the operation doesn't produce any blocks to write. [#77766](https://github.com/ClickHouse/ClickHouse/pull/77766) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Fixed refreshable materialized view in Replicated database not working on newly added replicas. [#77774](https://github.com/ClickHouse/ClickHouse/pull/77774) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix possible crash when `NOT_FOUND_COLUMN_IN_BLOCK` error occurs. [#77854](https://github.com/ClickHouse/ClickHouse/pull/77854) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Fix crash that happens in the S3/AzureQueue while filling data. [#77878](https://github.com/ClickHouse/ClickHouse/pull/77878) ([Bharat Nallan](https://github.com/bharatnc)).
* Disable fuzzy search for history in SSH server (since it requires the skim library). [#78002](https://github.com/ClickHouse/ClickHouse/pull/78002) ([Azat Khuzhin](https://github.com/azat)).
* Fixes a bug that a vector search query on a non-indexed column was returning incorrect results if there was another vector column in the table with a defined vector similarity index. (Issue [#77978](https://github.com/ClickHouse/ClickHouse/issues/77978)). [#78069](https://github.com/ClickHouse/ClickHouse/pull/78069) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Fix a minuscule error "The requested output format {} is binary... Do you want to output it anyway? \[y/N]" prompt. [#78095](https://github.com/ClickHouse/ClickHouse/pull/78095) ([Azat Khuzhin](https://github.com/azat)).
* Fix of a bug in case of `toStartOfInterval` with zero origin argument. [#78096](https://github.com/ClickHouse/ClickHouse/pull/78096) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Disallow specifying an empty `session_id` query parameter for HTTP interface. [#78098](https://github.com/ClickHouse/ClickHouse/pull/78098) ([Alexey Katsman](https://github.com/alexkats)).
* Fix metadata override in `Replicated` database which could have happened due to a `RENAME` query executed right after an `ALTER` query. [#78107](https://github.com/ClickHouse/ClickHouse/pull/78107) ([Nikolay Degterinsky](https://github.com/evillique)).
* Fix crash in `NATS` engine. [#78108](https://github.com/ClickHouse/ClickHouse/pull/78108) ([Dmitry Novikov](https://github.com/dmitry-sles-novikov)).
* Do not try to create history\_file in embedded client for SSH (in previous versions the creation was always unsuccessful, but attempted). [#78112](https://github.com/ClickHouse/ClickHouse/pull/78112) ([Azat Khuzhin](https://github.com/azat)).
* Fix `system.detached_tables` displaying incorrect information after `RENAME DATABASE` or `DROP TABLE` queries. [#78126](https://github.com/ClickHouse/ClickHouse/pull/78126) ([Nikolay Degterinsky](https://github.com/evillique)).
* Fix for checks for too many tables with `Replicated` database after [#77274](https://github.com/ClickHouse/ClickHouse/pull/77274). Also, perform the check before creating the storage to avoid creating unaccounted nodes in Keeper in the case of `ReplicatedMergeTree` or `KeeperMap`. [#78127](https://github.com/ClickHouse/ClickHouse/pull/78127) ([Nikolay Degterinsky](https://github.com/evillique)).
* Fix possible crash due to concurrent `S3Queue` metadata initialization. [#78131](https://github.com/ClickHouse/ClickHouse/pull/78131) ([Azat Khuzhin](https://github.com/azat)).
* `groupArray*` functions now produce `BAD_ARGUMENTS` error for Int-typed 0 value of the `max_size` argument, like it's already done for UInt one, instead of trying to execute with it. [#78140](https://github.com/ClickHouse/ClickHouse/pull/78140) ([Eduard Karacharov](https://github.com/korowa)).
* Prevent crash on recovering a lost replica if the local table is removed before it's detached. [#78173](https://github.com/ClickHouse/ClickHouse/pull/78173) ([Raúl Marín](https://github.com/Algunenano)).
* Fix the fact that "alterable" column in `system.s3_queue_settings` returning always `false`. [#78187](https://github.com/ClickHouse/ClickHouse/pull/78187) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Mask Azure access signature to be not visible to user or in logs. [#78189](https://github.com/ClickHouse/ClickHouse/pull/78189) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix prefetching of substreams with prefixes in Wide parts. [#78205](https://github.com/ClickHouse/ClickHouse/pull/78205) ([Pavel Kruglov](https://github.com/Avogar)).
* Fixed crashes / incorrect result for `mapFromArrays` in case of `LowCardinality(Nullable)` type of keys array. [#78240](https://github.com/ClickHouse/ClickHouse/pull/78240) ([Eduard Karacharov](https://github.com/korowa)).
* Fix delta-kernel-rs auth options. [#78255](https://github.com/ClickHouse/ClickHouse/pull/78255) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Not schedule Refreshable Materialized Views task if a replica's `disable_insertion_and_mutation` is true. A task is some insertion, it will failed if `disable_insertion_and_mutation` is true. [#78277](https://github.com/ClickHouse/ClickHouse/pull/78277) ([Xu Jia](https://github.com/XuJia0210)).
* Validate access to underlying tables for the `Merge` engine. [#78339](https://github.com/ClickHouse/ClickHouse/pull/78339) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
* `FINAL` modifier can be ignored when querying a `Distributed` table. [#78428](https://github.com/ClickHouse/ClickHouse/pull/78428) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* `bitmapMin` returns the uint32\_max when the bitmap is empty (and uint64\_max when the input type is larger), which matches the behavior of empty roaring\_bitmap's minimum. [#78444](https://github.com/ClickHouse/ClickHouse/pull/78444) ([wxybear](https://github.com/wxybear)).
* Disable parallelization of query processing right after reading FROM when `distributed_aggregation_memory_efficient` enabled, it may lead to logical error. Closes [#76934](https://github.com/ClickHouse/ClickHouse/issues/76934). [#78500](https://github.com/ClickHouse/ClickHouse/pull/78500) ([flynn](https://github.com/ucasfl)).
* Set at least one stream for reading in case there are zero planned streams after applying `max_streams_to_max_threads_ratio` setting. [#78505](https://github.com/ClickHouse/ClickHouse/pull/78505) ([Eduard Karacharov](https://github.com/korowa)).
* In storage `S3Queue` fix logical error "Cannot unregister: table uuid is not registered". Closes [#78285](https://github.com/ClickHouse/ClickHouse/issues/78285). [#78541](https://github.com/ClickHouse/ClickHouse/pull/78541) ([Kseniia Sumarokova](https://github.com/kssenii)).
* ClickHouse is now able to figure out its cgroup v2 on systems with both cgroups v1 and v2 enabled. [#78566](https://github.com/ClickHouse/ClickHouse/pull/78566) ([Grigory Korolev](https://github.com/gkorolev)).
* `-Cluster` table functions were failing when used with table-level settings. [#78587](https://github.com/ClickHouse/ClickHouse/pull/78587) ([Daniil Ivanik](https://github.com/divanik)).
* Better checks when transactions are not supported by ReplicatedMergeTree on INSERT. [#78633](https://github.com/ClickHouse/ClickHouse/pull/78633) ([Azat Khuzhin](https://github.com/azat)).
* Cleanup query settings during attach. [#78637](https://github.com/ClickHouse/ClickHouse/pull/78637) ([Raúl Marín](https://github.com/Algunenano)).
* Fix a crash when an invalid path was specified in `iceberg_metadata_file_path`. [#78688](https://github.com/ClickHouse/ClickHouse/pull/78688) ([alesapin](https://github.com/alesapin)).
* In `DeltaLake` table engine with delta-kernel-s implementation, fix the case when the read schema is different from the table schema and there are partition columns at the same time leading to a "not found column" error. [#78690](https://github.com/ClickHouse/ClickHouse/pull/78690) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix a problem when after scheduling to close a named session (but before timeout expiration), creation of a new named session with the same name led to it being closed at a time point when the first session was scheduled to close. [#78698](https://github.com/ClickHouse/ClickHouse/pull/78698) ([Alexey Katsman](https://github.com/alexkats)).
* Fixed several types of `SELECT` queries that read from tables with `MongoDB` engine or `mongodb` table function: queries with implicit conversion of const value in `WHERE` clause (e.g. `WHERE datetime = '2025-03-10 00:00:00'`) ; queries with `LIMIT` and `GROUP BY`. Previously, they could return the wrong result. [#78777](https://github.com/ClickHouse/ClickHouse/pull/78777) ([Anton Popov](https://github.com/CurtizJ)).
* Don't block table shutdown while running `CHECK TABLE`. [#78782](https://github.com/ClickHouse/ClickHouse/pull/78782) ([Raúl Marín](https://github.com/Algunenano)).
* Keeper fix: fix ephemeral count in all cases. [#78799](https://github.com/ClickHouse/ClickHouse/pull/78799) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix bad cast in `StorageDistributed` when using table functions other than `view`. Closes [#78464](https://github.com/ClickHouse/ClickHouse/issues/78464). [#78828](https://github.com/ClickHouse/ClickHouse/pull/78828) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fix the consistency of formatting for `tupleElement(*, 1)`. Closes [#78639](https://github.com/ClickHouse/ClickHouse/issues/78639). [#78832](https://github.com/ClickHouse/ClickHouse/pull/78832) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Dictionaries of type `ssd_cache` now reject zero or negative `block_size` and `write_buffer_size` parameters (issue [#78314](https://github.com/ClickHouse/ClickHouse/issues/78314)). [#78854](https://github.com/ClickHouse/ClickHouse/pull/78854) ([Elmi Ahmadov](https://github.com/ahmadov)).
* Fix crash in Refreshable MATERIALIZED VIEW inthe case of ALTER after an incorrect shutdown. [#78858](https://github.com/ClickHouse/ClickHouse/pull/78858) ([Azat Khuzhin](https://github.com/azat)).
* Fix parsing of bad `DateTime` values in `CSV` format. [#78919](https://github.com/ClickHouse/ClickHouse/pull/78919) ([Pavel Kruglov](https://github.com/Avogar)).
* Keeper fix: Avoid triggering watches on failed multi requests. [#79247](https://github.com/ClickHouse/ClickHouse/pull/79247) ([Antonio Andelic](https://github.com/antonio2368)).
* Fix reading Iceberg table failed when min-max value is specified explicitly but is `NULL`. The Go Iceberg library was noted for generating such an atrocious files. Closes [#78740](https://github.com/ClickHouse/ClickHouse/issues/78740). [#78764](https://github.com/ClickHouse/ClickHouse/pull/78764) ([flynn](https://github.com/ucasfl)).
#### Build/Testing/Packaging Improvement
* Respect CPU target features in Rust and enable LTO in all crates. [#78590](https://github.com/ClickHouse/ClickHouse/pull/78590) ([Raúl Marín](https://github.com/Algunenano)).
ClickHouse release 25.3 LTS, 2025-03-20
#### Backward Incompatible Change
* Disallow truncating replicated databases. [#76651](https://github.com/ClickHouse/ClickHouse/pull/76651) ([Bharat Nallan](https://github.com/bharatnc)).
* Skipping index cache is reverted. [#77447](https://github.com/ClickHouse/ClickHouse/pull/77447) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
#### New Feature
* `JSON` data type is production-ready. See [https://jsonbench.com/](https://jsonbench.com/). `Dynamic` and `Variant` data types are production-ready. [#77785](https://github.com/ClickHouse/ClickHouse/pull/77785) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Introduce the SSH protocol for clickhouse-server. Now, it is possible to connect to ClickHouse using any SSH client. This closes: [#74340](https://github.com/ClickHouse/ClickHouse/issues/74340). [#74989](https://github.com/ClickHouse/ClickHouse/pull/74989) ([George Gamezardashvili](https://github.com/Infjoker)).
* Replace table functions with their -Cluster alternatives if parallel replicas are enabled. Fixes [#65024](https://github.com/ClickHouse/ClickHouse/issues/65024). [#70659](https://github.com/ClickHouse/ClickHouse/pull/70659) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* A new implementation of the Userspace Page Cache, which allows caching data in the in-process memory instead of relying on the OS page cache, which is useful when the data is stored on a remote virtual filesystem without backing with the local filesystem cache. [#70509](https://github.com/ClickHouse/ClickHouse/pull/70509) ([Michael Kolupaev](https://github.com/al13n321)).
* Added `concurrent_threads_scheduler` server setting that governs how CPU slots are distributed among concurrent queries. Could be set to `round_robin` (previous behavior) or `fair_round_robin` to address the issue of unfair CPU distribution between INSERTs and SELECTs. [#75949](https://github.com/ClickHouse/ClickHouse/pull/75949) ([Sergei Trifonov](https://github.com/serxa)).
* Add `estimateCompressionRatio` aggregate function [#70801](https://github.com/ClickHouse/ClickHouse/issues/70801). [#76661](https://github.com/ClickHouse/ClickHouse/pull/76661) ([Tariq Almawash](https://github.com/talmawash)).
* Added function `arraySymmetricDifference`. It returns all elements from multiple array arguments which do not occur in all arguments. Example: `SELECT arraySymmetricDifference([1, 2], [2, 3])` returns `[1, 3]`. (issue [#61673](https://github.com/ClickHouse/ClickHouse/issues/61673)). [#76231](https://github.com/ClickHouse/ClickHouse/pull/76231) ([Filipp Abapolov](https://github.com/pheepa)).
* Allow to explicitly specify metadata file to read for Iceberg with storage/table function setting `iceberg_metadata_file_path `. Fixes [#47412](https://github.com/ClickHouse/ClickHouse/issues/47412). [#77318](https://github.com/ClickHouse/ClickHouse/pull/77318) ([alesapin](https://github.com/alesapin)).
* Added the `keccak256` hash function, commonly used in blockchain implementations, especially in EVM-based systems. [#76669](https://github.com/ClickHouse/ClickHouse/pull/76669) ([Arnaud Briche](https://github.com/arnaudbriche)).
* Add three new functions. `icebergTruncate` according to specification. [https://iceberg.apache.org/spec/#truncate-transform-details](https://iceberg.apache.org/spec/#truncate-transform-details), `toYearNumSinceEpoch` and `toMonthNumSinceEpoch`. Support `truncate` transform in partition pruning for `Iceberg` engine. [#77403](https://github.com/ClickHouse/ClickHouse/pull/77403) ([alesapin](https://github.com/alesapin)).
* Support `LowCardinality(Decimal)` data types [#72256](https://github.com/ClickHouse/ClickHouse/issues/72256). [#72833](https://github.com/ClickHouse/ClickHouse/pull/72833) ([zhanglistar](https://github.com/zhanglistar)).
* `FilterTransformPassedRows` and `FilterTransformPassedBytes` profile events will show the number of rows and number of bytes filtered during the query execution. [#76662](https://github.com/ClickHouse/ClickHouse/pull/76662) ([Onkar Deshpande](https://github.com/onkar)).
* Support for the histogram metric type. The interface closely mirrors the Prometheus client, where you simply call `observe(value)` to increment the counter in the bucket corresponding to the value. The histogram metrics are exposed via `system.histogram_metrics`. [#75736](https://github.com/ClickHouse/ClickHouse/pull/75736) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Non-constant CASE support for switching on explicit values. [#77399](https://github.com/ClickHouse/ClickHouse/pull/77399) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
#### Experimental Feature
* Add support [for Unity Catalog](https://www.databricks.com/product/unity-catalog) for DeltaLake tables on top of AWS S3 and local filesystem. [#76988](https://github.com/ClickHouse/ClickHouse/pull/76988) ([alesapin](https://github.com/alesapin)).
* Introduce experimental integration with AWS Glue service catalog for Iceberg tables. [#77257](https://github.com/ClickHouse/ClickHouse/pull/77257) ([alesapin](https://github.com/alesapin)).
* Added support for dynamic cluster autodiscovery. This extends the existing *node* autodiscovery feature. ClickHouse can now automatically detect and register new *clusters* under a common ZooKeeper path using ``. [#76001](https://github.com/ClickHouse/ClickHouse/pull/76001) ([Anton Ivashkin](https://github.com/ianton-ru)).
* Allow automatic cleanup merges of entire partitions after a configurable timeout with a new setting `enable_replacing_merge_with_cleanup_for_min_age_to_force_merge`. [#76440](https://github.com/ClickHouse/ClickHouse/pull/76440) ([Christoph Wurm](https://github.com/cwurm)).
#### Performance Improvement
* Implement query condition cache to improve query performance using repeated conditions. The range of the portion of data that does not meet the condition is remembered as a temporary index in memory. Subsequent queries will use this index. Close [#67768](https://github.com/ClickHouse/ClickHouse/issues/67768) [#69236](https://github.com/ClickHouse/ClickHouse/pull/69236) ([zhongyuankai](https://github.com/zhongyuankai)).
* Actively evict data from the cache on parts removal. Do not let the cache grow to the maximum size if the amount of data is less. [#76641](https://github.com/ClickHouse/ClickHouse/pull/76641) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Replace Int256 and UInt256 with clang builtin i256 in arithmetic calculation, and it gives a performance improvement [#70502](https://github.com/ClickHouse/ClickHouse/issues/70502). [#73658](https://github.com/ClickHouse/ClickHouse/pull/73658) ([李扬](https://github.com/taiyang-li)).
* In some cases (e.g. empty array column) data parts can contain empty files. We can skip writing empty blobs to ObjectStorage and only store metadata for such files when the table resides on disk with separated metadata and object storages. [#75860](https://github.com/ClickHouse/ClickHouse/pull/75860) ([Alexander Gololobov](https://github.com/davenger)).
* Improve min/max performance for Decimal32/Decimal64/DateTime64. [#76570](https://github.com/ClickHouse/ClickHouse/pull/76570) ([李扬](https://github.com/taiyang-li)).
* Query compilation (setting `compile_expressions`) now considers the machine type. This speeds up such queries significantly. [#76753](https://github.com/ClickHouse/ClickHouse/pull/76753) ([ZhangLiStar](https://github.com/zhanglistar)).
* Optimize `arraySort`. [#76850](https://github.com/ClickHouse/ClickHouse/pull/76850) ([李扬](https://github.com/taiyang-li)).
* Disable `filesystem_cache_prefer_bigger_buffer_size` when the cache is used passively, such as for merges. [#77898](https://github.com/ClickHouse/ClickHouse/pull/77898) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Apply `preserve_most` attribute at some places in code, which allows slightly better code generation. [#67778](https://github.com/ClickHouse/ClickHouse/pull/67778) ([Nikita Taranov](https://github.com/nickitat)).
* Faster ClickHouse servers shutdown (get rid of 2.5sec delay). [#76550](https://github.com/ClickHouse/ClickHouse/pull/76550) ([Azat Khuzhin](https://github.com/azat)).
* Avoid excess allocation in ReadBufferFromS3 and other remote reading buffers, reduce their memory consumption in half. [#76692](https://github.com/ClickHouse/ClickHouse/pull/76692) ([Sema Checherinda](https://github.com/CheSema)).
* Update zstd from 1.5.5 to 1.5.7 which could lead to some [performance improvements](https://github.com/facebook/zstd/releases/tag/v1.5.7). [#77137](https://github.com/ClickHouse/ClickHouse/pull/77137) ([Pradeep Chhetri](https://github.com/chhetripradeep)).
* Reduce memory usage during prefetches of JSON column in Wide parts. This is relevant when ClickHouse is used on top of a shared storage, such as in ClickHouse Cloud. [#77640](https://github.com/ClickHouse/ClickHouse/pull/77640) ([Pavel Kruglov](https://github.com/Avogar)).
#### Improvement
* Support atomic rename when `TRUNCATE` is used with `INTO OUTFILE`. Resolves [#70323](https://github.com/ClickHouse/ClickHouse/issues/70323). [#77181](https://github.com/ClickHouse/ClickHouse/pull/77181) ([Onkar Deshpande](https://github.com/onkar)).
* It's no longer possible to use `NaN` or `inf` for float values as settings. Not like it did make any sense before. [#77546](https://github.com/ClickHouse/ClickHouse/pull/77546) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Disable parallel replicas by default when analyzer is disabled regardless `compatibility` setting. It's still possible to change this behavior by explicitly setting `parallel_replicas_only_with_analyzer` to `false`. [#77115](https://github.com/ClickHouse/ClickHouse/pull/77115) ([Igor Nikonov](https://github.com/devcrafter)).
* Add the ability to define a list of headers that are forwarded from the headers of the client request to the external HTTP authenticator. [#77054](https://github.com/ClickHouse/ClickHouse/pull/77054) ([inv2004](https://github.com/inv2004)).
* Respect column insensitive column matching for fields in tuple columns. Close [https://github.com/apache/incubator-gluten/issues/8324](https://github.com/apache/incubator-gluten/issues/8324). [#73780](https://github.com/ClickHouse/ClickHouse/pull/73780) ([李扬](https://github.com/taiyang-li)).
* Parameters for the codec Gorilla will now always be saved in the table metadata in .sql file. This closes: [#70072](https://github.com/ClickHouse/ClickHouse/issues/70072). [#74814](https://github.com/ClickHouse/ClickHouse/pull/74814) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Implemented parsing enhancements for certain data lakes (Sequence ID parsing: Added functionality to parse sequence identifiers in manifest files AND Avro metadata parsing: Redesigned the Avro metadata parser to be easily extendable for future enhancements). [#75010](https://github.com/ClickHouse/ClickHouse/pull/75010) ([Daniil Ivanik](https://github.com/divanik)).
* Remove trace\_id from default ORDER BY for `system.opentelemetry_span_log`. [#75907](https://github.com/ClickHouse/ClickHouse/pull/75907) ([Azat Khuzhin](https://github.com/azat)).
* Encryption (the attribute `encrypted_by`) can now be applied to any configuration file (config.xml, users.xml, nested configuration files). Previously, it worked only for the top-level config.xml file. [#75911](https://github.com/ClickHouse/ClickHouse/pull/75911) ([Mikhail Gorshkov](https://github.com/mgorshkov)).
* Improve the `system.warnings` table and add some dynamic warning messages that can be added, updated or removed. [#76029](https://github.com/ClickHouse/ClickHouse/pull/76029) ([Bharat Nallan](https://github.com/bharatnc)).
* This PR makes it impossible to run a query `ALTER USER user1 ADD PROFILES a, DROP ALL PROFILES` because all `DROP` operations should come first in the order. [#76242](https://github.com/ClickHouse/ClickHouse/pull/76242) ([pufit](https://github.com/pufit)).
* Various enhancements for SYNC REPLICA (better error messages, better tests, sanity checks). [#76307](https://github.com/ClickHouse/ClickHouse/pull/76307) ([Azat Khuzhin](https://github.com/azat)).
* Use correct fallback when multipart copy to S3 fails during backup with Access Denied. Multi part copy can generate Access Denied error when backup is done between buckets that have different credentials. [#76515](https://github.com/ClickHouse/ClickHouse/pull/76515) ([Antonio Andelic](https://github.com/antonio2368)).
* Upgraded librdkafka (which is a pile of crap) to version 2.8.0 (the pile does not get any better) and improved the shutdown sequence for Kafka tables, reducing delays during table drops and server restarts. The `engine=Kafka` no longer explicitly leaves the consumer group when a table is dropped. Instead, the consumer remains in the group until it is automatically removed after `session_timeout_ms` (default: 45 seconds) of inactivity. [#76621](https://github.com/ClickHouse/ClickHouse/pull/76621) ([filimonov](https://github.com/filimonov)).
* Fix validation of S3 request settings. [#76658](https://github.com/ClickHouse/ClickHouse/pull/76658) ([Vitaly Baranov](https://github.com/vitlibar)).
* System tables like `server_settings` or `settings` have a `default` value column which is convenient. Add them to `merge_tree_settings` and `replicated_merge_tree_settings`. [#76942](https://github.com/ClickHouse/ClickHouse/pull/76942) ([Diego Nieto](https://github.com/lesandie)).
* Added `ProfileEvents::QueryPreempted`, which has a similar logic to `CurrentMetrics::QueryPreempted`. [#77015](https://github.com/ClickHouse/ClickHouse/pull/77015) ([VicoWu](https://github.com/VicoWu)).
* Previously, a Replicated database could print credentials specified in a query to logs. This behaviour is fixed. This closes: [#77123](https://github.com/ClickHouse/ClickHouse/issues/77123). [#77133](https://github.com/ClickHouse/ClickHouse/pull/77133) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Allow ALTER TABLE DROP PARTITION for `plain_rewritable disk`. [#77138](https://github.com/ClickHouse/ClickHouse/pull/77138) ([Julia Kartseva](https://github.com/jkartseva)).
* Backup/restore setting `allow_s3_native_copy` now supports value three possible values: - `False` - s3 native copy will not be used; - `True` (old default) - ClickHouse will try s3 native copy first, if it fails then fallback to the reading+writing approach; - `'auto'` (new default) - ClickHouse will compare the source and destination credentials first. If they are same, ClickHouse will try s3 native copy and then may fallback to the reading+writing approach. If they are different, ClickHouse will go directly to the reading+writing approach. [#77401](https://github.com/ClickHouse/ClickHouse/pull/77401) ([Vitaly Baranov](https://github.com/vitlibar)).
* Support aws session token and environment credentials usage in delta kernel for DeltaLake table engine. [#77661](https://github.com/ClickHouse/ClickHouse/pull/77661) ([Kseniia Sumarokova](https://github.com/kssenii)).
#### Bug Fix (user-visible misbehavior in an official stable release)
* Fix stuck while processing pending batch for async distributed INSERT (due to i.e. `No such file or directory`). [#72939](https://github.com/ClickHouse/ClickHouse/pull/72939) ([Azat Khuzhin](https://github.com/azat)).
* Improved datetime conversion during index analysis by enforcing saturating behavior for implicit Date to DateTime conversions. This resolves potential index analysis inaccuracies caused by datetime range limitations. This fixes [#73307](https://github.com/ClickHouse/ClickHouse/issues/73307). It also fixes explicit `toDateTime` conversion when `date_time_overflow_behavior = 'ignore'` which is the default value. [#73326](https://github.com/ClickHouse/ClickHouse/pull/73326) ([Amos Bird](https://github.com/amosbird)).
* Fix all sort of bugs due to race between UUID and table names (for instance it will fix the race between `RENAME` and `RESTART REPLICA`, in case of concurrent `RENAME` with `SYSTEM RESTART REPLICA` you may get end up restarting wrong replica, or/and leaving one of the tables in a `Table X is being restarted` state). [#76308](https://github.com/ClickHouse/ClickHouse/pull/76308) ([Azat Khuzhin](https://github.com/azat)).
* Fix data loss when enable async insert and insert into ... from file ... with unequal block size if the first block size \< async\_max\_size but the second block > async\_max\_size, the second block will not be inserted. these data is left in `squashing`. [#76343](https://github.com/ClickHouse/ClickHouse/pull/76343) ([Han Fei](https://github.com/hanfei1991)).
* Renamed field 'marks' to 'marks\_bytes' in `system.data_skipping_indices`. [#76374](https://github.com/ClickHouse/ClickHouse/pull/76374) ([Robert Schulze](https://github.com/rschu1ze)).
* Fix dynamic filesystem cache resize handling unexpected errors during eviction. [#76466](https://github.com/ClickHouse/ClickHouse/pull/76466) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fixed `used_flag` initialization in parallel hash. It might cause a server crash. [#76580](https://github.com/ClickHouse/ClickHouse/pull/76580) ([Nikita Taranov](https://github.com/nickitat)).
* Fix a logical error when calling `defaultProfiles` function inside a projection. [#76627](https://github.com/ClickHouse/ClickHouse/pull/76627) ([pufit](https://github.com/pufit)).
* Do not request interactive basic auth in the browser in Web UI. Closes [#76319](https://github.com/ClickHouse/ClickHouse/issues/76319). [#76637](https://github.com/ClickHouse/ClickHouse/pull/76637) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix THERE\_IS\_NO\_COLUMN exception when selecting boolean literal from distributed tables. [#76656](https://github.com/ClickHouse/ClickHouse/pull/76656) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* The subpath inside the table directory is chosen in a more profound way. [#76681](https://github.com/ClickHouse/ClickHouse/pull/76681) ([Daniil Ivanik](https://github.com/divanik)).
* Fix an error `Not found column in block` after altering a table with a subcolumn in PK. After [https://github.com/ClickHouse/ClickHouse/pull/72644](https://github.com/ClickHouse/ClickHouse/pull/72644), requires [https://github.com/ClickHouse/ClickHouse/pull/74403](https://github.com/ClickHouse/ClickHouse/pull/74403). [#76686](https://github.com/ClickHouse/ClickHouse/pull/76686) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Add performance tests for null shortcircuit and fix bugs. [#76708](https://github.com/ClickHouse/ClickHouse/pull/76708) ([李扬](https://github.com/taiyang-li)).
* Flush output write buffers before finalizing them. Fix `LOGICAL_ERROR` generated during the finalization of some output format, e.g. `JSONEachRowWithProgressRowOutputFormat`. [#76726](https://github.com/ClickHouse/ClickHouse/pull/76726) ([Antonio Andelic](https://github.com/antonio2368)).
* Added support for MongoDB's binary UUID ([#74452](https://github.com/ClickHouse/ClickHouse/issues/74452)) - Fixed WHERE pushdown to MongoDB when using the table function ([#72210](https://github.com/ClickHouse/ClickHouse/issues/72210)) - Changed the MongoDB - ClickHouse type mapping such that MongoDB's binary UUID can only be parsed to ClickHouse's UUID. This should avoid ambiguities and surprises in future. - Fixed OID mapping, preserving backward compatibility. [#76762](https://github.com/ClickHouse/ClickHouse/pull/76762) ([Kirill Nikiforov](https://github.com/allmazz)).
* Fix exception handling in parallel prefixes deserialization of JSON subcolumns. [#76809](https://github.com/ClickHouse/ClickHouse/pull/76809) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix lgamma function behavior for negative integers. [#76840](https://github.com/ClickHouse/ClickHouse/pull/76840) ([Ilya Kataev](https://github.com/IlyaKataev)).
* Fix reverse key analysis for explicitly defined primary keys. Similar to [#76654](https://github.com/ClickHouse/ClickHouse/issues/76654). [#76846](https://github.com/ClickHouse/ClickHouse/pull/76846) ([Amos Bird](https://github.com/amosbird)).
* Fix pretty print of Bool values in JSON format. [#76905](https://github.com/ClickHouse/ClickHouse/pull/76905) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix possible crash because of bad JSON column rollback on error during async inserts. [#76908](https://github.com/ClickHouse/ClickHouse/pull/76908) ([Pavel Kruglov](https://github.com/Avogar)).
* Previously, `multiIf` may return different types of columns during planning and main execution. This resulted in code producing undefined behavior from the C++ perspective. [#76914](https://github.com/ClickHouse/ClickHouse/pull/76914) ([Nikita Taranov](https://github.com/nickitat)).
* Fixed incorrect serialization of constant nullable keys in MergeTree. This fixes [#76939](https://github.com/ClickHouse/ClickHouse/issues/76939). [#76985](https://github.com/ClickHouse/ClickHouse/pull/76985) ([Amos Bird](https://github.com/amosbird)).
* Fix sorting of `BFloat16` values. This closes [#75487](https://github.com/ClickHouse/ClickHouse/issues/75487). This closes [#75669](https://github.com/ClickHouse/ClickHouse/issues/75669). [#77000](https://github.com/ClickHouse/ClickHouse/pull/77000) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Bug fix JSON with Variant subcolumn by adding check to skip ephemeral subcolumns in part consistency check. [#72187](https://github.com/ClickHouse/ClickHouse/issues/72187). [#77034](https://github.com/ClickHouse/ClickHouse/pull/77034) ([Smita Kulkarni](https://github.com/SmitaRKulkarni)).
* Fix crash in template parsing in Values format in case of types mismatch. [#77071](https://github.com/ClickHouse/ClickHouse/pull/77071) ([Pavel Kruglov](https://github.com/Avogar)).
* Don't allow creating EmbeddedRocksDB table with subcolumn in primary key. Previosly such table could be created but select queries were failing. [#77074](https://github.com/ClickHouse/ClickHouse/pull/77074) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix illegal comparison in distributed queries because pushing down predicates to remote doesn't respect literal types. [#77093](https://github.com/ClickHouse/ClickHouse/pull/77093) ([Duc Canh Le](https://github.com/canhld94)).
* Fix crash during Kafka table creation with exception. [#77121](https://github.com/ClickHouse/ClickHouse/pull/77121) ([Pavel Kruglov](https://github.com/Avogar)).
* Support JSON and subcolumns in Kafka and RabbitMQ engines. [#77122](https://github.com/ClickHouse/ClickHouse/pull/77122) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix exceptions stack unwinding on MacOS. [#77126](https://github.com/ClickHouse/ClickHouse/pull/77126) ([Eduard Karacharov](https://github.com/korowa)).
* Fix reading 'null' subcolumn in getSubcolumn function. [#77163](https://github.com/ClickHouse/ClickHouse/pull/77163) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix bloom filter index with Array and not supported functions. [#77271](https://github.com/ClickHouse/ClickHouse/pull/77271) ([Pavel Kruglov](https://github.com/Avogar)).
* We should only check the restriction on the amount of tables during the initial CREATE query. [#77274](https://github.com/ClickHouse/ClickHouse/pull/77274) ([Nikolay Degterinsky](https://github.com/evillique)).
* Not a bug: `SELECT toBFloat16(-0.0) == toBFloat16(0.0)` now correctly returns `true` (from previously `false`). This makes the behavior consistent with `Float32` and `Float64`. [#77290](https://github.com/ClickHouse/ClickHouse/pull/77290) ([Shankar Iyer](https://github.com/shankar-iyer)).
* Fix posbile incorrect reference to unintialized key\_index variable, which may lead to crash in debug builds (this uninitialized reference won't cause issues in release builds because subsequent code are likely to throw errors.) ### documentation entry for user-facing changes. [#77305](https://github.com/ClickHouse/ClickHouse/pull/77305) ([wxybear](https://github.com/wxybear)).
* Fix name for partition with a Bool value. It was broken in [https://github.com/ClickHouse/ClickHouse/pull/74533](https://github.com/ClickHouse/ClickHouse/pull/74533). [#77319](https://github.com/ClickHouse/ClickHouse/pull/77319) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix comparison between tuples with nullable elements inside and strings. As an example, before the change comparison between a Tuple `(1, null)` and a String `'(1,null)'` would result in an error. Another example would be a comparison between a Tuple `(1, a)`, where `a` is a Nullable column, and a String `'(1, 2)'`. This change addresses these issues. [#77323](https://github.com/ClickHouse/ClickHouse/pull/77323) ([Alexey Katsman](https://github.com/alexkats)).
* Fix crash in ObjectStorageQueueSource. Was intoduced in [https://github.com/ClickHouse/ClickHouse/pull/76358](https://github.com/ClickHouse/ClickHouse/pull/76358). [#77325](https://github.com/ClickHouse/ClickHouse/pull/77325) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix `async_insert` with `input`. [#77340](https://github.com/ClickHouse/ClickHouse/pull/77340) ([Azat Khuzhin](https://github.com/azat)).
* Fix: `WITH FILL` may fail with NOT\_FOUND\_COLUMN\_IN\_BLOCK when sorting column is removed by planer. Similar issue related to inconsistent DAG calculated for INTERPOLATE expression. [#77343](https://github.com/ClickHouse/ClickHouse/pull/77343) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Fix several LOGICAL\_ERRORs around setting alias of invalid AST nodes. [#77445](https://github.com/ClickHouse/ClickHouse/pull/77445) ([Raúl Marín](https://github.com/Algunenano)).
* In filesystem cache impementation fix error processing during file segment write. [#77471](https://github.com/ClickHouse/ClickHouse/pull/77471) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Make DatabaseIceberg use correct metadata file provided by catalog. Closes [#75187](https://github.com/ClickHouse/ClickHouse/issues/75187). [#77486](https://github.com/ClickHouse/ClickHouse/pull/77486) ([Kseniia Sumarokova](https://github.com/kssenii)).
* The query cache now assumes that UDFs are non-deterministic. Accordingly, results of queries with UDFs are no longer cached. Previously, users were able to define non-deterministic UDFs whose result would erronously be cached (issue [#77553](https://github.com/ClickHouse/ClickHouse/issues/77553)). [#77633](https://github.com/ClickHouse/ClickHouse/pull/77633) ([Jimmy Aguilar Mena](https://github.com/Ergus)).
* Fix system.filesystem\_cache\_log working only under setting `enable_filesystem_cache_log`. [#77650](https://github.com/ClickHouse/ClickHouse/pull/77650) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix a logical error when calling `defaultRoles` function inside a projection. Follow-up for [#76627](https://github.com/ClickHouse/ClickHouse/issues/76627). [#77667](https://github.com/ClickHouse/ClickHouse/pull/77667) ([pufit](https://github.com/pufit)).
* Second arguments of type `Nullable` for function `arrayResize` are now disallowed. Previously, anything from errors to wrong results could happen with `Nullable` as second argument. (issue [#48398](https://github.com/ClickHouse/ClickHouse/issues/48398)). [#77724](https://github.com/ClickHouse/ClickHouse/pull/77724) ([Manish Gill](https://github.com/mgill25)).
* Regularly check if merges and mutations were cancelled even in case when the operation doesn't produce any blocks to write. [#77766](https://github.com/ClickHouse/ClickHouse/pull/77766) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
#### Build/Testing/Packaging Improvement
* `clickhouse-odbc-bridge` and `clickhouse-library-bridge` are moved to a separate repository, [https://github.com/ClickHouse/odbc-bridge/](https://github.com/ClickHouse/odbc-bridge/). [#76225](https://github.com/ClickHouse/ClickHouse/pull/76225) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix Rust cross-compilation and allow disabling Rust completely. [#76921](https://github.com/ClickHouse/ClickHouse/pull/76921) ([Raúl Marín](https://github.com/Algunenano)).
ClickHouse release 25.2, 2025-02-27
#### Backward Incompatible Change
* Completely enable `async_load_databases` by default (even for those installations that do not upgrade `config.xml`). [#74772](https://github.com/ClickHouse/ClickHouse/pull/74772) ([Azat Khuzhin](https://github.com/azat)).
* Add `JSONCompactEachRowWithProgress` and `JSONCompactStringsEachRowWithProgress` formats. Continuation of [#69989](https://github.com/ClickHouse/ClickHouse/issues/69989). The `JSONCompactWithNames` and `JSONCompactWithNamesAndTypes` no longer output "totals" - apparently, it was a mistake in the implementation. [#75037](https://github.com/ClickHouse/ClickHouse/pull/75037) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Change the `format_alter_operations_with_parentheses` default to true to disambiguate the ALTER commands list (see [https://github.com/ClickHouse/ClickHouse/pull/59532](https://github.com/ClickHouse/ClickHouse/pull/59532)). This breaks replication with clusters prior to 24.3. If you are upgrading a cluster using older releases turn off the setting in the server config or upgrade to 24.3 first. [#75302](https://github.com/ClickHouse/ClickHouse/pull/75302) ([Raúl Marín](https://github.com/Algunenano)).
* Remove the possibility of filtering log messages using regular expressions. The implementation introduced a data race, so it has to be removed. [#75577](https://github.com/ClickHouse/ClickHouse/pull/75577) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* The setting `min_chunk_bytes_for_parallel_parsing` cannot be zero anymore. This fixes: [#71110](https://github.com/ClickHouse/ClickHouse/issues/71110). [#75239](https://github.com/ClickHouse/ClickHouse/pull/75239) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Validate settings in the cache configuration. Non existing settings were ignored before, now they will throw an error and they should be removed. [#75452](https://github.com/ClickHouse/ClickHouse/pull/75452) ([Kseniia Sumarokova](https://github.com/kssenii)).
#### New Feature
* Support type `Nullable(JSON)`. [#73556](https://github.com/ClickHouse/ClickHouse/pull/73556) ([Pavel Kruglov](https://github.com/Avogar)).
* Support subcolumns in the DEFAULT and MATERIALIZED expressions. [#74403](https://github.com/ClickHouse/ClickHouse/pull/74403) ([Pavel Kruglov](https://github.com/Avogar)).
* Support writing Parquet bloom filters using the `output_format_parquet_write_bloom_filter` setting (enabled by default). [#71681](https://github.com/ClickHouse/ClickHouse/pull/71681) ([Michael Kolupaev](https://github.com/al13n321)).
* Web UI now has interactive database navigation. [#75777](https://github.com/ClickHouse/ClickHouse/pull/75777) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Allow the combination of read-only and read-write disks in the storage policy (as multiple volumes or multiple disks). This allows data to be read from the entire volume, while inserts will prefer the writable disk (i.e., Copy-on-Write storage policy). [#75862](https://github.com/ClickHouse/ClickHouse/pull/75862) ([Azat Khuzhin](https://github.com/azat)).
* Add a new Database engine, `DatabaseBackup,` that allows to instantly attach table/database from backup. [#75725](https://github.com/ClickHouse/ClickHouse/pull/75725) ([Maksim Kita](https://github.com/kitaisreal)).
* Support prepared statements in the Postgres wire protocol. [#75035](https://github.com/ClickHouse/ClickHouse/pull/75035) ([scanhex12](https://github.com/scanhex12)).
* Add the ability to ATTACH tables without a database layer, which is useful for MergeTree tables located on Web, S3, and similar external virtual filesystems. [#75788](https://github.com/ClickHouse/ClickHouse/pull/75788) ([Azat Khuzhin](https://github.com/azat)).
* Add a new string comparison function, `compareSubstrings` to compare parts of two strings. Example: `SELECT compareSubstrings('Saxony', 'Anglo-Saxon', 0, 6, 5) AS result` means "compare 6 bytes of strings 'Saxon' and 'Anglo-Saxon' lexicographically, starting at offset 0 in the first string, offset 5 in the second string". [#74070](https://github.com/ClickHouse/ClickHouse/pull/74070) ([lgbo](https://github.com/lgbo-ustc)).
* A new function, `initialQueryStartTime` is added. It returns the start time of the current query. The value is the same across all shards during a distributed query. [#75087](https://github.com/ClickHouse/ClickHouse/pull/75087) ([Roman Lomonosov](https://github.com/lomik)).
* Add support for SSL authentication with named collections for MySQL. Closes [#59111](https://github.com/ClickHouse/ClickHouse/issues/59111). [#59452](https://github.com/ClickHouse/ClickHouse/pull/59452) ([Nikolay Degterinsky](https://github.com/evillique)).
#### Experimental Features
* Added a new setting, `enable_adaptive_memory_spill_scheduler` that allows multiple Grace JOINs in the same query to monitor their combined memory footprint and trigger spilling into external storage adaptively to prevent MEMORY\_LIMIT\_EXCEEDED. [#72728](https://github.com/ClickHouse/ClickHouse/pull/72728) ([lgbo](https://github.com/lgbo-ustc)).
* Make the new, experimental `Kafka` table engine fully respect Keeper feature flags. [#76004](https://github.com/ClickHouse/ClickHouse/pull/76004) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Restore the (Intel) QPL codec, which was removed in v24.10 due to licensing issues. [#76021](https://github.com/ClickHouse/ClickHouse/pull/76021) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* For the integration with HDFS added support for the `dfs.client.use.datanode.hostname` configuration option. [#74635](https://github.com/ClickHouse/ClickHouse/pull/74635) ([Mikhail Tiukavkin](https://github.com/freshertm)).
#### Performance Improvement
* Improve performance of the whole JSON column reading in Wide parts from S3. It's done by adding prefetches for subcolumn prefixes deserialization, cache of deserialized prefixes, and parallel deserialization of subcolumn prefixes. It improves the reading of the JSON column from S3 4 times in queries like `SELECT data FROM table` and about 10 times in queries like `SELECT data FROM table LIMIT 10`. [#74827](https://github.com/ClickHouse/ClickHouse/pull/74827) ([Pavel Kruglov](https://github.com/Avogar)).
* Fixed unnecessary contention in `parallel_hash` when `max_rows_in_join = max_bytes_in_join = 0`. [#75155](https://github.com/ClickHouse/ClickHouse/pull/75155) ([Nikita Taranov](https://github.com/nickitat)).
* Fixed double preallocation in `ConcurrentHashJoin` in case join sides are swapped by the optimizer. [#75149](https://github.com/ClickHouse/ClickHouse/pull/75149) ([Nikita Taranov](https://github.com/nickitat)).
* Slight improvement in some join scenarios: precalculate the number of output rows and reserve memory for them. [#75376](https://github.com/ClickHouse/ClickHouse/pull/75376) ([Alexander Gololobov](https://github.com/davenger)).
* For queries like `WHERE a < b AND b < c AND c < 5`, we can infer new comparing conditions (`a < 5 AND b < 5`) to have better filter ability. [#73164](https://github.com/ClickHouse/ClickHouse/pull/73164) ([Shichao Jin](https://github.com/jsc0218)).
* Keeper improvement: disable digest calculation when committing to in-memory storage for better performance. It can be enabled with `keeper_server.digest_enabled_on_commit` config. Digest is still calculated when preprocessing requests. [#75490](https://github.com/ClickHouse/ClickHouse/pull/75490) ([Antonio Andelic](https://github.com/antonio2368)).
* Push down filter expression from JOIN ON when possible. [#75536](https://github.com/ClickHouse/ClickHouse/pull/75536) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Calculate columns and indices sizes lazily in MergeTree. [#75938](https://github.com/ClickHouse/ClickHouse/pull/75938) ([Pavel Kruglov](https://github.com/Avogar)).
* Reintroduce respect `ttl_only_drop_parts` on `MATERIALIZE TTL`; only read necessary columns to recalculate TTL and drop parts by replacing them with an empty ones. [#72751](https://github.com/ClickHouse/ClickHouse/pull/72751) ([Andrey Zvonov](https://github.com/zvonand)).
* Reduce write buffer size for plain\_rewritable metadata files [#75758](https://github.com/ClickHouse/ClickHouse/pull/75758) ([Julia Kartseva](https://github.com/jkartseva)).
* Reduce memory usage for some window functions. [#65647](https://github.com/ClickHouse/ClickHouse/pull/65647) ([lgbo](https://github.com/lgbo-ustc)).
* Evaluate parquet bloom filters and min/max indexes together. Necessary to properly support: `x = 3 or x > 5` where data = \[1, 2, 4, 5]. [#71383](https://github.com/ClickHouse/ClickHouse/pull/71383) ([Arthur Passos](https://github.com/arthurpassos)).
* Queries passed to the `Executable` storage are no longer limited to a single-threaded execution. [#70084](https://github.com/ClickHouse/ClickHouse/pull/70084) ([yawnt](https://github.com/yawnt)).
* Fetch parts in parallel in ALTER TABLE FETCH PARTITION (thread pool size is controlled with `max_fetch_partition_thread_pool_size`). [#74978](https://github.com/ClickHouse/ClickHouse/pull/74978) ([Azat Khuzhin](https://github.com/azat)).
* Allow to move predicates with the `indexHint` function to `PREWHERE`. [#74987](https://github.com/ClickHouse/ClickHouse/pull/74987) ([Anton Popov](https://github.com/CurtizJ)).
#### Improvement
* Fixed calculation of size in memory for `LowCardinality` columns. [#74688](https://github.com/ClickHouse/ClickHouse/pull/74688) ([Nikita Taranov](https://github.com/nickitat)).
* `processors_profile_log` table now has a default configuration with a TTL of 30 days. [#66139](https://github.com/ClickHouse/ClickHouse/pull/66139) ([Ilya Yatsishin](https://github.com/qoega)).
* Allow naming shards in the cluster configuration. [#72276](https://github.com/ClickHouse/ClickHouse/pull/72276) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* Change Prometheus remote write response success status from 200/OK to 204/NoContent. [#74170](https://github.com/ClickHouse/ClickHouse/pull/74170) ([Michael Dempsey](https://github.com/bluestealth)).
* Add ability to reload `max_remote_read_network_bandwidth_for_serve` and `max_remote_write_network_bandwidth_for_server` on the fly without restart server. [#74206](https://github.com/ClickHouse/ClickHouse/pull/74206) ([Kai Zhu](https://github.com/nauu)).
* Allow using blob paths to calculate checksums while making a backup. [#74729](https://github.com/ClickHouse/ClickHouse/pull/74729) ([Vitaly Baranov](https://github.com/vitlibar)).
* Added a query ID column to `system.query_cache` (closes [#68205](https://github.com/ClickHouse/ClickHouse/issues/68205)). [#74982](https://github.com/ClickHouse/ClickHouse/pull/74982) ([NamHoaiNguyen](https://github.com/NamHoaiNguyen)).
* It is allowed to cancel `ALTER TABLE ... FREEZE ...` queries with `KILL QUERY` and automatically by a timeout (`max_execution_time`). [#75016](https://github.com/ClickHouse/ClickHouse/pull/75016) ([Kirill](https://github.com/kirillgarbar)).
* Add support for `groupUniqArrayArrayMap` as `SimpleAggregateFunction`. [#75034](https://github.com/ClickHouse/ClickHouse/pull/75034) ([Miel Donkers](https://github.com/mdonkers)).
* Hide catalog credential settings in database engine `Iceberg`. Closes [#74559](https://github.com/ClickHouse/ClickHouse/issues/74559). [#75080](https://github.com/ClickHouse/ClickHouse/pull/75080) ([Kseniia Sumarokova](https://github.com/kssenii)).
* `intExp2` / `intExp10`: Define undefined behaviour: return 0 for too small argument, `18446744073709551615` for too big argument, throw exception if `nan`. [#75312](https://github.com/ClickHouse/ClickHouse/pull/75312) ([Vitaly Baranov](https://github.com/vitlibar)).
* Support `s3.endpoint` natively from catalog config in `DatabaseIceberg`. Closes [#74558](https://github.com/ClickHouse/ClickHouse/issues/74558). [#75375](https://github.com/ClickHouse/ClickHouse/pull/75375) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Don't fail silently if a user executing `SYSTEM DROP REPLICA` doesn't have enough permissions. [#75377](https://github.com/ClickHouse/ClickHouse/pull/75377) ([Bharat Nallan](https://github.com/bharatnc)).
* Add a ProfileEvent about the number of times any of the system logs have failed to flush. [#75466](https://github.com/ClickHouse/ClickHouse/pull/75466) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add a check and extra logging for decrypting and decompressing. [#75471](https://github.com/ClickHouse/ClickHouse/pull/75471) ([Vitaly Baranov](https://github.com/vitlibar)).
* Added support for the micro sign (U+00B5) in the `parseTimeDelta` function. Now both the micro sign (U+00B5) and the Greek letter mu (U+03BC) are recognized as valid representations for microseconds, aligning ClickHouse's behavior with Go’s implementation ([see time.go](https://github.com/golang/go/blob/ad7b46ee4ac1cee5095d64b01e8cf7fcda8bee5e/src/time/time.go#L983C19-L983C20) and [time/format.go](https://github.com/golang/go/blob/ad7b46ee4ac1cee5095d64b01e8cf7fcda8bee5e/src/time/format.go#L1608-L1609)). [#75472](https://github.com/ClickHouse/ClickHouse/pull/75472) ([Vitaly Orlov](https://github.com/orloffv)).
* Replace server setting (`send_settings_to_client`) with client setting (`apply_settings_from_server`) that controls whether client-side code (e.g., parsing INSERT data and formatting query output) should use settings from server's `users.xml` and user profile. Otherwise, only settings from the client command line, session, and query are used. Note that this only applies to native client (not e.g. HTTP), and doesn't apply to most of query processing (which happens on the server). [#75478](https://github.com/ClickHouse/ClickHouse/pull/75478) ([Michael Kolupaev](https://github.com/al13n321)).
* Better error messages for syntax errors. Previously, if the query was too large, and the token whose length exceeds the limit is a very large string literal, the message about the reason was lost in the middle of two examples of this very long token. Fix the issue when a query with UTF-8 was cut incorrectly in the error message. Fix excessive quoting of query fragments. This closes [#75473](https://github.com/ClickHouse/ClickHouse/issues/75473). [#75561](https://github.com/ClickHouse/ClickHouse/pull/75561) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add profile events in storage `S3(Azure)Queue`. [#75618](https://github.com/ClickHouse/ClickHouse/pull/75618) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Disable sending settings from server to client (`send_settings_to_client=false`) for compatibility (This feature will be re-implemented as a client setting later for better usability). [#75648](https://github.com/ClickHouse/ClickHouse/pull/75648) ([Michael Kolupaev](https://github.com/al13n321)).
* Add a config `memory_worker_correct_memory_tracker` to enable correction of the internal memory tracker with information from different sources read in the background thread periodically. [#75714](https://github.com/ClickHouse/ClickHouse/pull/75714) ([Antonio Andelic](https://github.com/antonio2368)).
* Add column `normalized_query_hash` into `system.processes`. Note: while it can be easily calculated on the fly with the `normalizedQueryHash` function, this is needed to prepare for subsequent changes. [#75756](https://github.com/ClickHouse/ClickHouse/pull/75756) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Querying `system.tables` will not throw even if there is a `Merge` table created over a database that no longer exists. Remove the `getTotalRows` method from `Hive` tables because we don't allow it to do complex work. [#75772](https://github.com/ClickHouse/ClickHouse/pull/75772) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Store start\_time/end\_time for Backups with microseconds. [#75929](https://github.com/ClickHouse/ClickHouse/pull/75929) ([Aleksandr Musorin](https://github.com/AVMusorin)).
* Add `MemoryTrackingUncorrected` metric showing the value of the internal global memory tracker which is not corrected by RSS. [#75935](https://github.com/ClickHouse/ClickHouse/pull/75935) ([Antonio Andelic](https://github.com/antonio2368)).
* Allow parsing endpoints like `localhost:1234/handle` in `PostgreSQL` or `MySQL` table functions. This fixes a regression introduced in [https://github.com/ClickHouse/ClickHouse/pull/52503](https://github.com/ClickHouse/ClickHouse/pull/52503). [#75944](https://github.com/ClickHouse/ClickHouse/pull/75944) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Added a server setting `throw_on_unknown_workload` that allows to choose behavior on query with `workload` setting set to unknown value: either allow unlimited access (default) or throw a `RESOURCE_ACCESS_DENIED` error. It is useful to force all queries to use workload scheduling. [#75999](https://github.com/ClickHouse/ClickHouse/pull/75999) ([Sergei Trifonov](https://github.com/serxa)).
* Don't rewrite subcolumns to `getSubcolumn` in `ARRAY JOIN` if not necessary. [#76018](https://github.com/ClickHouse/ClickHouse/pull/76018) ([Pavel Kruglov](https://github.com/Avogar)).
* Retry coordination errors when loading tables. [#76020](https://github.com/ClickHouse/ClickHouse/pull/76020) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Support flushing individual logs in `SYSTEM FLUSH LOGS`. [#76132](https://github.com/ClickHouse/ClickHouse/pull/76132) ([Raúl Marín](https://github.com/Algunenano)).
* Improved the `/binary` server's page. Using the Hilbert curve instead of the Morton curve. Display 512 MB worth of addresses in the square, which fills the square better (in previous versions, addresses fill only half of the square). Color addresses closer to the library name rather than the function name. Allow scrolling a bit more outside of the area. [#76192](https://github.com/ClickHouse/ClickHouse/pull/76192) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Retry ON CLUSTER queries in case of TOO\_MANY\_SIMULTANEOUS\_QUERIES. [#76352](https://github.com/ClickHouse/ClickHouse/pull/76352) ([Patrick Galbraith](https://github.com/CaptTofu)).
* Add the `CPUOverload` asynchronous metric, which calculates the server's relative CPU deficit. [#76404](https://github.com/ClickHouse/ClickHouse/pull/76404) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Changed the default value of `output_format_pretty_max_rows` from 10000 to 1000. I think it is better for usability. [#76407](https://github.com/ClickHouse/ClickHouse/pull/76407) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
#### Bug Fix (user-visible misbehavior in an official stable release)
* Fix formatting of exceptions using a custom format if they appear during query interpretation. In previous versions, exceptions were formatted using the default format rather than the format specified in the query. This closes [#55422](https://github.com/ClickHouse/ClickHouse/issues/55422). [#74994](https://github.com/ClickHouse/ClickHouse/pull/74994) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix type mapping for SQLite (integer types into `int64`, floating points into `float64`). [#73853](https://github.com/ClickHouse/ClickHouse/pull/73853) ([Joanna Hulboj](https://github.com/jh0x)).
* Fix identifier resolution from parent scopes. Allow the use of aliases to expressions in the WITH clause. Fixes [#58994](https://github.com/ClickHouse/ClickHouse/issues/58994). Fixes [#62946](https://github.com/ClickHouse/ClickHouse/issues/62946). Fixes [#63239](https://github.com/ClickHouse/ClickHouse/issues/63239). Fixes [#65233](https://github.com/ClickHouse/ClickHouse/issues/65233). Fixes [#71659](https://github.com/ClickHouse/ClickHouse/issues/71659). Fixes [#71828](https://github.com/ClickHouse/ClickHouse/issues/71828). Fixes [#68749](https://github.com/ClickHouse/ClickHouse/issues/68749). [#66143](https://github.com/ClickHouse/ClickHouse/pull/66143) ([Dmitry Novik](https://github.com/novikd)).
* Fix negate function monotonicity. In previous versions, the query `select * from a where -x = -42;` where `x` is the primary key, can return a wrong result. [#71440](https://github.com/ClickHouse/ClickHouse/pull/71440) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix empty tuple handling in arrayIntersect. This fixes [#72578](https://github.com/ClickHouse/ClickHouse/issues/72578). [#72581](https://github.com/ClickHouse/ClickHouse/pull/72581) ([Amos Bird](https://github.com/amosbird)).
* Fix reading JSON sub-object subcolumns with incorrect prefix. [#73182](https://github.com/ClickHouse/ClickHouse/pull/73182) ([Pavel Kruglov](https://github.com/Avogar)).
* Propagate Native format settings properly for client-server communication. [#73924](https://github.com/ClickHouse/ClickHouse/pull/73924) ([Pavel Kruglov](https://github.com/Avogar)).
* Check for not supported types for some storages. [#74218](https://github.com/ClickHouse/ClickHouse/pull/74218) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix crash with query `INSERT INTO SELECT` over PostgreSQL interface on macOS (issue [#72938](https://github.com/ClickHouse/ClickHouse/issues/72938)). [#74231](https://github.com/ClickHouse/ClickHouse/pull/74231) ([Artem Yurov](https://github.com/ArtemYurov)).
* Fixed uninitialized max\_log\_ptr in the replicated database. [#74336](https://github.com/ClickHouse/ClickHouse/pull/74336) ([Konstantin Morozov](https://github.com/k-morozov)).
* Fix crash when inserting interval (issue [#74299](https://github.com/ClickHouse/ClickHouse/issues/74299)). [#74478](https://github.com/ClickHouse/ClickHouse/pull/74478) ([NamHoaiNguyen](https://github.com/NamHoaiNguyen)).
* Fix formatting constant JSON literals. Previously it could lead to syntax errors during sending the query to another server. [#74533](https://github.com/ClickHouse/ClickHouse/pull/74533) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix broken create query when using constant partition expressions with implicit projections enabled. This fixes [#74596](https://github.com/ClickHouse/ClickHouse/issues/74596) . [#74634](https://github.com/ClickHouse/ClickHouse/pull/74634) ([Amos Bird](https://github.com/amosbird)).
* Avoid leaving connection in broken state after INSERT finishes with exception. [#74740](https://github.com/ClickHouse/ClickHouse/pull/74740) ([Azat Khuzhin](https://github.com/azat)).
* Avoid reusing connections that had been left in the intermediate state. [#74749](https://github.com/ClickHouse/ClickHouse/pull/74749) ([Azat Khuzhin](https://github.com/azat)).
* Fix crash during JSON type declaration parsing when type name is not uppercase. [#74784](https://github.com/ClickHouse/ClickHouse/pull/74784) ([Pavel Kruglov](https://github.com/Avogar)).
* Keeper: fix logical\_error when the connection had been terminated before establishing. [#74844](https://github.com/ClickHouse/ClickHouse/pull/74844) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix a behavior when the server couldn't startup when there's a table using `AzureBlobStorage`. Tables are loaded without any requests to Azure. [#74880](https://github.com/ClickHouse/ClickHouse/pull/74880) ([Alexey Katsman](https://github.com/alexkats)).
* Fix missing `used_privileges` and `missing_privileges` fields in `query_log` for BACKUP and RESTORE operations. [#74887](https://github.com/ClickHouse/ClickHouse/pull/74887) ([Alexey Katsman](https://github.com/alexkats)).
* HDFS refresh krb ticket if sasl error during hdfs select request. [#74930](https://github.com/ClickHouse/ClickHouse/pull/74930) ([inv2004](https://github.com/inv2004)).
* Fix queries to Replicated database in startup\_scripts. [#74942](https://github.com/ClickHouse/ClickHouse/pull/74942) ([Azat Khuzhin](https://github.com/azat)).
* Fix issues with expressions type aliased in the JOIN ON clause when a null-safe comparison is used. [#74970](https://github.com/ClickHouse/ClickHouse/pull/74970) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Revert part's state from deleting back to outdated when remove operation has failed. [#74985](https://github.com/ClickHouse/ClickHouse/pull/74985) ([Sema Checherinda](https://github.com/CheSema)).
* In previous versions, when there was a scalar subquery, we started writing the progress (accumulated from processing the subquery) during the initialization of the data format, which was before HTTP headers were written. This led to the loss of HTTP headers, such as X-ClickHouse-QueryId and X-ClickHouse-Format, as well as Content-Type. [#74991](https://github.com/ClickHouse/ClickHouse/pull/74991) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix `CREATE TABLE AS...` queries for `database_replicated_allow_replicated_engine_arguments=0`. [#75000](https://github.com/ClickHouse/ClickHouse/pull/75000) ([Bharat Nallan](https://github.com/bharatnc)).
* Fix leaving connection in a bad state in client after INSERT exceptions. [#75030](https://github.com/ClickHouse/ClickHouse/pull/75030) ([Azat Khuzhin](https://github.com/azat)).
* Fix crash due to uncaught exception in PSQL replication. [#75062](https://github.com/ClickHouse/ClickHouse/pull/75062) ([Azat Khuzhin](https://github.com/azat)).
* Sasl can fail any rpc call, the fix helps to repeat the call in case if krb5 ticker is expired. [#75063](https://github.com/ClickHouse/ClickHouse/pull/75063) ([inv2004](https://github.com/inv2004)).
* Fixed usage of indexes (primary and secondary) for `Array`, `Map` and `Nullable(..)` columns with enabled setting `optimize_function_to_subcolumns`. Previously, indexes for these columns could have been ignored. [#75081](https://github.com/ClickHouse/ClickHouse/pull/75081) ([Anton Popov](https://github.com/CurtizJ)).
* Disable `flatten_nested` when creating materialized views with inner tables since it will not be possible to use such flattened columns. [#75085](https://github.com/ClickHouse/ClickHouse/pull/75085) ([Christoph Wurm](https://github.com/cwurm)).
* Fix for some of IPv6 addresses (such as ::ffff:1.1.1.1) in forwarded\_for field is wrongly interpreted resulting in client disconnect with exception. [#75133](https://github.com/ClickHouse/ClickHouse/pull/75133) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Fix nullsafe JOIN handling for LowCardinality nullable data type. Previously JOIN ON with nullsafe comparison, such as `IS NOT DISTINCT FROM`, `<=>` , `a IS NULL AND b IS NULL OR a == b` didn't work correctly with LowCardinality columns. [#75143](https://github.com/ClickHouse/ClickHouse/pull/75143) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Checks that we don't specify key\_condition when counting total\_number\_of\_rows for NumRowsCache. [#75164](https://github.com/ClickHouse/ClickHouse/pull/75164) ([Daniil Ivanik](https://github.com/divanik)).
* Fix queries with unused interpolation with the new analyzer. [#75173](https://github.com/ClickHouse/ClickHouse/pull/75173) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Fix the crash bug of CTE with Insert. [#75188](https://github.com/ClickHouse/ClickHouse/pull/75188) ([Shichao Jin](https://github.com/jsc0218)).
* Keeper fix: avoid writing to broken changelogs when rolling back logs. [#75197](https://github.com/ClickHouse/ClickHouse/pull/75197) ([Antonio Andelic](https://github.com/antonio2368)).
* Use `BFloat16` as a supertype where appropriate. This closes: [#74404](https://github.com/ClickHouse/ClickHouse/issues/74404). [#75236](https://github.com/ClickHouse/ClickHouse/pull/75236) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Fix unexpected defaults in join result with any\_join\_distinct\_right\_table\_keys and OR in JOIN ON. [#75262](https://github.com/ClickHouse/ClickHouse/pull/75262) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Mask azureblobstorage table engine credentials. [#75319](https://github.com/ClickHouse/ClickHouse/pull/75319) ([Garrett Thomas](https://github.com/garrettthomaskth)).
* Fixed behavior when ClickHouse may erroneously do a filter pushdown to an external database like PostgreSQL, MySQL, or SQLite. This closes: [#71423](https://github.com/ClickHouse/ClickHouse/issues/71423). [#75320](https://github.com/ClickHouse/ClickHouse/pull/75320) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Fix crash in protobuf schema cache that can happen during output in Protobuf format and parallel query `SYSTEM DROP FORMAT SCHEMA CACHE`. [#75357](https://github.com/ClickHouse/ClickHouse/pull/75357) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix a possible logical error or uninitialized memory issue when a filter from `HAVING` is pushed down with parallel replicas. [#75363](https://github.com/ClickHouse/ClickHouse/pull/75363) ([Vladimir Cherkasov](https://github.com/vdimir)).
* Hide sensitive info for `icebergS3`, `icebergAzure` table functions and table engines. [#75378](https://github.com/ClickHouse/ClickHouse/pull/75378) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Function `TRIM` with computed empty trim characters are now correctly handled. Example: `SELECT TRIM(LEADING concat('') FROM 'foo')` (Issue [#69922](https://github.com/ClickHouse/ClickHouse/issues/69922)). [#75399](https://github.com/ClickHouse/ClickHouse/pull/75399) ([Manish Gill](https://github.com/mgill25)).
* Fix data race in IOutputFormat. [#75448](https://github.com/ClickHouse/ClickHouse/pull/75448) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix possible error `Elements ... and ... of Nested data structure ... (Array columns) have different array sizes` when JSON subcolumns with Array type are used in JOIN over distributed tables. [#75512](https://github.com/ClickHouse/ClickHouse/pull/75512) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix data corruption with `CODEC(ZSTD, DoubleDelta)`. Closes [#70031](https://github.com/ClickHouse/ClickHouse/issues/70031). [#75548](https://github.com/ClickHouse/ClickHouse/pull/75548) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fix interaction between allow\_feature\_tier and compatibility mergetree setting. [#75635](https://github.com/ClickHouse/ClickHouse/pull/75635) ([Raúl Marín](https://github.com/Algunenano)).
* Fix incorrect processed\_rows value in system.s3queue\_log in case file was retried. [#75666](https://github.com/ClickHouse/ClickHouse/pull/75666) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Respect `materialized_views_ignore_errors` when a materialized view writes to a URL engine and there is a connectivity issue. [#75679](https://github.com/ClickHouse/ClickHouse/pull/75679) ([Christoph Wurm](https://github.com/cwurm)).
* Fixed rare crashes while reading from `MergeTree` table after multiple asynchronous `RENAME` queries (with `alter_sync = 0`) between columns with different types. [#75693](https://github.com/ClickHouse/ClickHouse/pull/75693) ([Anton Popov](https://github.com/CurtizJ)).
* Fix `Block structure mismatch in QueryPipeline stream` error for some queries with `UNION ALL`. [#75715](https://github.com/ClickHouse/ClickHouse/pull/75715) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Rebuild projection on alter modify of its PK column. Previously it could lead to `CANNOT_READ_ALL_DATA` errors during selects after alter modify of the column used in projection PK. [#75720](https://github.com/ClickHouse/ClickHouse/pull/75720) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix incorrect result of `ARRAY JOIN` for scalar subqueries (with analyzer). [#75732](https://github.com/ClickHouse/ClickHouse/pull/75732) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fixed null pointer dereference in `DistinctSortedStreamTransform`. [#75734](https://github.com/ClickHouse/ClickHouse/pull/75734) ([Nikita Taranov](https://github.com/nickitat)).
* Fix `allow_suspicious_ttl_expressions` behaviour. [#75771](https://github.com/ClickHouse/ClickHouse/pull/75771) ([Aleksei Filatov](https://github.com/aalexfvk)).
* Fix uninitialized memory read in function `translate`. This closes [#75592](https://github.com/ClickHouse/ClickHouse/issues/75592). [#75794](https://github.com/ClickHouse/ClickHouse/pull/75794) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Propagate format settings to JSON as string formatting in Native format. [#75832](https://github.com/ClickHouse/ClickHouse/pull/75832) ([Pavel Kruglov](https://github.com/Avogar)).
* Recorded the default enablement of parallel hash as join algorithm in v24.12 in the settings change history. This means that ClickHouse will continue to join using non-parallel hash if an older compatibility level than v24.12 is configured. [#75870](https://github.com/ClickHouse/ClickHouse/pull/75870) ([Robert Schulze](https://github.com/rschu1ze)).
* Fixed a bug that tables with implicitly added min-max indices could not be copied into a new table (issue [#75677](https://github.com/ClickHouse/ClickHouse/issues/75677)). [#75877](https://github.com/ClickHouse/ClickHouse/pull/75877) ([Smita Kulkarni](https://github.com/SmitaRKulkarni)).
* `clickhouse-library-bridge` allows opening arbitrary libraries from the filesystem, which makes it safe to run only inside an isolated environment. To prevent a vulnerability when it is run near the clickhouse-server, we will limit the paths of libraries to a location, provided in the configuration. This vulnerability was found with the [ClickHouse Bug Bounty Program](https://github.com/ClickHouse/ClickHouse/issues/38986) by **Arseniy Dugin**. [#75954](https://github.com/ClickHouse/ClickHouse/pull/75954) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* We happened to use JSON serialization for some metadata, which was a mistake, because JSON does not support binary data inside string literals, including zero bytes. SQL queries can contain binary data and invalid UTF-8, so we have to support this in our metadata files as well. At the same time, ClickHouse's `JSONEachRow` and similar formats work around that by deviating from the JSON standard in favor of a perfect roundtrip for the binary data. See the motivation here: [https://github.com/ClickHouse/ClickHouse/pull/73668#issuecomment-2560501790](https://github.com/ClickHouse/ClickHouse/pull/73668#issuecomment-2560501790). The solution is to make `Poco::JSON` library consistent with the JSON format serialization in ClickHouse. This closes [#73668](https://github.com/ClickHouse/ClickHouse/issues/73668). [#75963](https://github.com/ClickHouse/ClickHouse/pull/75963) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix check for commit limits in storage `S3Queue`. [#76104](https://github.com/ClickHouse/ClickHouse/pull/76104) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix attaching MergeTree tables with auto indexes (`add_minmax_index_for_numeric_columns`/`add_minmax_index_for_string_columns`). [#76139](https://github.com/ClickHouse/ClickHouse/pull/76139) ([Azat Khuzhin](https://github.com/azat)).
* Fixed issue of stack traces from parent threads of a job (`enable_job_stack_trace` setting) are not printed out. Fixed issue `enable_job_stack_trace` setting is not properly propagated to the threads resulting stack trace content not always respects this setting. [#76191](https://github.com/ClickHouse/ClickHouse/pull/76191) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Fix incorrect permission check where `ALTER RENAME` required `CREATE USER` grant. Closes [#74372](https://github.com/ClickHouse/ClickHouse/issues/74372). [#76241](https://github.com/ClickHouse/ClickHouse/pull/76241) ([pufit](https://github.com/pufit)).
* Fix reinterpretAs with FixedString on big-endian architecture. [#76253](https://github.com/ClickHouse/ClickHouse/pull/76253) ([Azat Khuzhin](https://github.com/azat)).
* Fix logical error in S3Queue "Expected current processor {} to be equal to {} for bucket {}". [#76358](https://github.com/ClickHouse/ClickHouse/pull/76358) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix deadlock for ALTER with Memory database. [#76359](https://github.com/ClickHouse/ClickHouse/pull/76359) ([Azat Khuzhin](https://github.com/azat)).
* Fix logical error in index analysis if condition in `WHERE` has `pointInPolygon` function. [#76360](https://github.com/ClickHouse/ClickHouse/pull/76360) ([Anton Popov](https://github.com/CurtizJ)).
* Fix potentially unsafe call in signal handler. [#76549](https://github.com/ClickHouse/ClickHouse/pull/76549) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Fix reverse key support in PartsSplitter. This fixes [#73400](https://github.com/ClickHouse/ClickHouse/issues/73400). [#73418](https://github.com/ClickHouse/ClickHouse/pull/73418) ([Amos Bird](https://github.com/amosbird)).
#### Build/Testing/Packaging Improvement
* Support build HDFS on both ARM and Intel Mac. [#74244](https://github.com/ClickHouse/ClickHouse/pull/74244) ([Yan Xin](https://github.com/yxheartipp)).
* Enable ICU and GRPC when cross-compiling for Darwin. [#75922](https://github.com/ClickHouse/ClickHouse/pull/75922) ([Raúl Marín](https://github.com/Algunenano)).
* Update to embedded LLVM 19. [#75148](https://github.com/ClickHouse/ClickHouse/pull/75148) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Disable network access for user default in the docker image. [#75259](https://github.com/ClickHouse/ClickHouse/pull/75259) ([Mikhail f. Shiryaev](https://github.com/Felixoid)). Make all clickhouse-server related actions a function, and execute them only when launching the default binary in `entrypoint.sh`. A long-postponed improvement was suggested in [#50724](https://github.com/ClickHouse/ClickHouse/issues/50724). Added switch `--users` to `clickhouse-extract-from-config` to get values from the `users.xml`. [#75643](https://github.com/ClickHouse/ClickHouse/pull/75643) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
* Remove about 20MB of dead code from the binary. [#76226](https://github.com/ClickHouse/ClickHouse/pull/76226) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
ClickHouse release 25.1, 2025-01-28
#### Backward Incompatible Change
* `JSONEachRowWithProgress` will write the progress whenever the progress happens. In previous versions, the progress was shown only after each block of the result, which made it useless. Change the way how the progress is displayed: it will not show zero values. This closes [#70800](https://github.com/ClickHouse/ClickHouse/issues/70800). [#73834](https://github.com/ClickHouse/ClickHouse/pull/73834) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* `Merge` tables will unify the structure of underlying tables by using a union of their columns and deriving common types. This closes [#64864](https://github.com/ClickHouse/ClickHouse/issues/64864). In certain cases, this change could be backward incompatible. One example is when there is no common type between tables, but conversion to the type of the first table is still possible, such as in the case of UInt64 and Int64 or any numeric type and String. If you want to return to the old behavior, set `merge_table_max_tables_to_look_for_schema_inference` to `1` or set `compatibility` to `24.12` or earlier. [#73956](https://github.com/ClickHouse/ClickHouse/pull/73956) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Parquet output format converts Date and DateTime columns to date/time types supported by Parquet, instead of writing them as raw numbers. `DateTime` becomes `DateTime64(3)` (was: `UInt32`); setting `output_format_parquet_datetime_as_uint32` brings back the old behavior. `Date` becomes `Date32` (was: `UInt16`). [#70950](https://github.com/ClickHouse/ClickHouse/pull/70950) ([Michael Kolupaev](https://github.com/al13n321)).
* Don't allow not comparable types (like `JSON`/`Object`/`AggregateFunction`) in `ORDER BY` and comparison functions `less/greater/equal/etc` by default. [#73276](https://github.com/ClickHouse/ClickHouse/pull/73276) ([Pavel Kruglov](https://github.com/Avogar)).
* The obsolete `MaterializedMySQL` database engine has been removed and is no longer available. [#73879](https://github.com/ClickHouse/ClickHouse/pull/73879) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* The `mysql` dictionary source no longer does `SHOW TABLE STATUS` query, because it does not provide any value for InnoDB tables, as long as for any recent MySQL versions. This closes [#72636](https://github.com/ClickHouse/ClickHouse/issues/72636). This change is backward compatible, but put in this category so you have a chance to notice it. [#73914](https://github.com/ClickHouse/ClickHouse/pull/73914) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* `CHECK TABLE` queries now require a separate, `CHECK` grant. In previous versions, it was enough to have `SHOW TABLES` grant to run these queries. But a `CHECK TABLE` query can be heavy, and usual query complexity limits for `SELECT` queries don't apply to it. It led to the potential of DoS. [#74471](https://github.com/ClickHouse/ClickHouse/pull/74471) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Function `h3ToGeo()` now returns the results in the order `(lat, lon)` (which is the standard order for geometric functions). Users who wish to retain the legacy result order `(lon, lat)` can set setting `h3togeo_lon_lat_result_order = true`. [#74719](https://github.com/ClickHouse/ClickHouse/pull/74719) ([Manish Gill](https://github.com/mgill25)).
* A new MongoDB driver is now the default. Users who like to continue using the legacy driver can set server setting `use_legacy_mongodb_integration` to true. [#73359](https://github.com/ClickHouse/ClickHouse/pull/73359) ([Robert Schulze](https://github.com/rschu1ze)).
#### New Feature
* Added an ability to apply non-finished (not materialized by background process) mutations during the execution of `SELECT` queries immediately after submitting. It can be enabled by setting `apply_mutations_on_fly`. [#74877](https://github.com/ClickHouse/ClickHouse/pull/74877) ([Anton Popov](https://github.com/CurtizJ)).
* Implement `Iceberg` tables partition pruning for time-related transform partition operations in Iceberg. [#72044](https://github.com/ClickHouse/ClickHouse/pull/72044) ([Daniil Ivanik](https://github.com/divanik)).
* Support subcolumns in MergeTree sorting key and skip indexes. [#72644](https://github.com/ClickHouse/ClickHouse/pull/72644) ([Pavel Kruglov](https://github.com/Avogar)).
* Support reading `HALF_FLOAT` values from `Apache Arrow`/`Parquet`/`ORC` (they are read into `Float32`). This closes [#72960](https://github.com/ClickHouse/ClickHouse/issues/72960). Keep in mind that IEEE-754 half float is not the same as `BFloat16`. Closes [#73835](https://github.com/ClickHouse/ClickHouse/issues/73835). [#73836](https://github.com/ClickHouse/ClickHouse/pull/73836) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* The `system.trace_log` table will contain two new columns, `symbols` and `lines` containing symbolized stack trace. It allows for easy collection and export of profile information. This is controlled by the server configuration value `symbolize` inside `trace_log` and is enabled by default. [#73896](https://github.com/ClickHouse/ClickHouse/pull/73896) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add a new function, `generateSerialID`, which can be used to generate auto-incremental numbers in tables. Continuation of [#64310](https://github.com/ClickHouse/ClickHouse/issues/64310) by [kazalika](https://github.com/kazalika). This closes [#62485](https://github.com/ClickHouse/ClickHouse/issues/62485). [#73950](https://github.com/ClickHouse/ClickHouse/pull/73950) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add syntax `query1 PARALLEL WITH query2 PARALLEL WITH query3 ... PARALLEL WITH queryN` for DDL queries. That means subqueries `{query1, query2, ... queryN}` are allowed to run in parallel with each other (and it's preferable). [#73983](https://github.com/ClickHouse/ClickHouse/pull/73983) ([Vitaly Baranov](https://github.com/vitlibar)).
* Added an in-memory cache for deserialized skipping index granules. This should make repeated queries that use skipping indexes faster. The size of the new cache is controlled by server settings `skipping_index_cache_size` and `skipping_index_cache_max_entries`. The original motivation for the cache were vector similarity indexes which became a lot faster now. [#70102](https://github.com/ClickHouse/ClickHouse/pull/70102) ([Robert Schulze](https://github.com/rschu1ze)).
* Now, the embedded Web UI has a progress bar during query runtime. It allows cancelling queries. It displays the total number of records and the extended information about the speed. The table can be rendered incrementally as soon as data arrives. Enable HTTP compression. Rendering of the table became faster. The table header became sticky. It allows selecting cells and navigating them by arrow keys. Fix the issue when the outline of the selected cell makes it smaller. Cells no longer expand on mouse hover but only on selection. The moment to stop rendering the incoming data is decided on the client rather than on the server side. Highlight digit groups for numbers. The overall design was refreshed and became bolder. It checks if the server is reachable and the correctness of credentials and displays the server version and uptime. The cloud icon is contoured in every font, even in Safari. Big integers inside nested data types will be rendered better. It will display inf/nan correctly. It will display data types when the mouse is over a column header. [#74204](https://github.com/ClickHouse/ClickHouse/pull/74204) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add the ability to create min-max (skipping) indices by default for columns managed by MergeTree using settings `add_minmax_index_for_numeric_columns` (for numeric columns) and `add_minmax_index_for_string_columns` (for string columns). For now, both settings are disabled, so there is no behavior change yet. [#74266](https://github.com/ClickHouse/ClickHouse/pull/74266) ([Smita Kulkarni](https://github.com/SmitaRKulkarni)).
* Add `script_query_number` and `script_line_number` fields to `system.query_log`, to the ClientInfo in the native protocol, and to server logs. This closes [#67542](https://github.com/ClickHouse/ClickHouse/issues/67542). Credits to [pinsvin00](https://github.com/pinsvin00) for kicking off this feature earlier in [#68133](https://github.com/ClickHouse/ClickHouse/issues/68133). [#74477](https://github.com/ClickHouse/ClickHouse/pull/74477) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Added aggregation function `sequenceMatchEvents` which return timestamps of matched events for longest chain of events in pattern. [#72349](https://github.com/ClickHouse/ClickHouse/pull/72349) ([UnamedRus](https://github.com/UnamedRus)).
* Added function `arrayNormalizedGini`. [#72823](https://github.com/ClickHouse/ClickHouse/pull/72823) ([flynn](https://github.com/ucasfl)).
* Add minus operator support for `DateTime64`, to allow subtraction between `DateTime64` values, as well as `DateTime`. [#74482](https://github.com/ClickHouse/ClickHouse/pull/74482) ([Li Yin](https://github.com/liyinsg)).
#### Experimental Features
* The `BFloat16` data type is production-ready. [#73840](https://github.com/ClickHouse/ClickHouse/pull/73840) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
#### Performance Improvement
* Optimized function `indexHint`. Now, columns that are only used as arguments of function `indexHint` are not read from the table. [#74314](https://github.com/ClickHouse/ClickHouse/pull/74314) ([Anton Popov](https://github.com/CurtizJ)). If the `indexHint` function is a central piece of your enterprise data architecture, this optimization will save your life.
* More accurate accounting for `max_joined_block_size_rows` setting for `parallel_hash` JOIN algorithm. Helps to avoid increased memory consumption compared to `hash` algorithm. [#74630](https://github.com/ClickHouse/ClickHouse/pull/74630) ([Nikita Taranov](https://github.com/nickitat)).
* Support predicate push down optimization on the query plan level for the `MergingAggregated` step. It improves performance for some queries with the analyzer. [#74073](https://github.com/ClickHouse/ClickHouse/pull/74073) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Splitting of left table blocks by hash was removed from the probe phase of the `parallel_hash` JOIN algorithm. [#73089](https://github.com/ClickHouse/ClickHouse/pull/73089) ([Nikita Taranov](https://github.com/nickitat)).
* Optimize RowBinary input format. Closes [#63805](https://github.com/ClickHouse/ClickHouse/issues/63805). [#65059](https://github.com/ClickHouse/ClickHouse/pull/65059) ([Pavel Kruglov](https://github.com/Avogar)).
* Write parts with level 1 if `optimize_on_insert` is enabled. It allows to use several optimizations of queries with `FINAL` for freshly written parts. [#73132](https://github.com/ClickHouse/ClickHouse/pull/73132) ([Anton Popov](https://github.com/CurtizJ)).
* Speedup string deserialization by some low-level optimisation. [#65948](https://github.com/ClickHouse/ClickHouse/pull/65948) ([Nikita Taranov](https://github.com/nickitat)).
* When running an equality comparison between records, such as during merges, start to compare rows from most likely unequal columns first. [#63780](https://github.com/ClickHouse/ClickHouse/pull/63780) ([UnamedRus](https://github.com/UnamedRus)).
* Improve grace hash join performance by re-ranking the right join table by keys. [#72237](https://github.com/ClickHouse/ClickHouse/pull/72237) ([kevinyhzou](https://github.com/KevinyhZou)).
* Allow `arrayROCAUC` and `arrayAUCPR` to compute partial area of the whole curve, so that its calculation can be parallelized over huge datasets. [#72904](https://github.com/ClickHouse/ClickHouse/pull/72904) ([Emmanuel](https://github.com/emmanuelsdias)).
* Avoid spawn too many idle threads. [#72920](https://github.com/ClickHouse/ClickHouse/pull/72920) ([Guo Wangyang](https://github.com/guowangy)).
* Don't list blob storage keys if we only have curly brackets expansion in table function. Closes [#73333](https://github.com/ClickHouse/ClickHouse/issues/73333). [#73518](https://github.com/ClickHouse/ClickHouse/pull/73518) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Short circuit optimization for functions executed over Nullable arguments. [#73820](https://github.com/ClickHouse/ClickHouse/pull/73820) ([李扬](https://github.com/taiyang-li)).
* Do not apply `maskedExecute` on non-function columns, improve the performance of short circuit execution. [#73965](https://github.com/ClickHouse/ClickHouse/pull/73965) ([lgbo](https://github.com/lgbo-ustc)).
* Disable the autodetection of headers in input formats for `Kafka`/`NATS`/`RabbitMQ`/`FileLog` to improve performance. [#74006](https://github.com/ClickHouse/ClickHouse/pull/74006) ([Azat Khuzhin](https://github.com/azat)).
* Execute pipeline with a higher degree of parallelism after aggregation with grouping sets. [#74082](https://github.com/ClickHouse/ClickHouse/pull/74082) ([Nikita Taranov](https://github.com/nickitat)).
* Reduce critical section in `MergeTreeReadPool`. [#74202](https://github.com/ClickHouse/ClickHouse/pull/74202) ([Guo Wangyang](https://github.com/guowangy)).
* Parallel replicas performance improvement. Packets deserialization on query initiator, for packets not related to parallel replicas protocol, now always happens in pipeline thread. Before, it could happen in a thread responsible for pipeline scheduling, which could make initiator less responsive and delay pipeline execution. [#74398](https://github.com/ClickHouse/ClickHouse/pull/74398) ([Igor Nikonov](https://github.com/devcrafter)).
* Improve performance of larger multi requests in Keeper. [#74849](https://github.com/ClickHouse/ClickHouse/pull/74849) ([Antonio Andelic](https://github.com/antonio2368)).
* Use log wrappers by value and don't allocate them in a heap. [#74034](https://github.com/ClickHouse/ClickHouse/pull/74034) ([Mikhail Artemenko](https://github.com/Michicosun)).
* Reestablish connection to MySQL and Postgres dictionary replicas in the background, so it wouldn't delay requests to corresponding dictionaries. [#71101](https://github.com/ClickHouse/ClickHouse/pull/71101) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Parallel replicas used historical information about replica availability to improve replica selection but did not update the replica's error count when the connection was unavailable. This PR updates the replica's error count when unavailable. [#72666](https://github.com/ClickHouse/ClickHouse/pull/72666) ([zoomxi](https://github.com/zoomxi)).
* Added a merge tree setting `materialize_skip_indexes_on_merge` which suppresses the creation of skip indexes during merge. This allows you to control explicitly (via `ALTER TABLE [..] MATERIALIZE INDEX [...]`) when skip indexes are created. This can be useful if skip indexes are expensive to build (e.g. vector similarity indexes). [#74401](https://github.com/ClickHouse/ClickHouse/pull/74401) ([Robert Schulze](https://github.com/rschu1ze)).
* Optimize keeper requests in Storage(S3/Azure)Queue. [#74410](https://github.com/ClickHouse/ClickHouse/pull/74410) ([Kseniia Sumarokova](https://github.com/kssenii)). [#74538](https://github.com/ClickHouse/ClickHouse/pull/74538) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Use up to `1000` parallel replicas by default. [#74504](https://github.com/ClickHouse/ClickHouse/pull/74504) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Improve HTTP session reuse when reading from s3 disk ([#72401](https://github.com/ClickHouse/ClickHouse/issues/72401)). [#74548](https://github.com/ClickHouse/ClickHouse/pull/74548) ([Julian Maicher](https://github.com/jmaicher)).
#### Improvement
* Support SETTINGS in a CREATE TABLE query with an implicit ENGINE and support mixing engine and query settings. [#73120](https://github.com/ClickHouse/ClickHouse/pull/73120) ([Raúl Marín](https://github.com/Algunenano)).
* Enable `use_hive_partitioning` by default. [#71636](https://github.com/ClickHouse/ClickHouse/pull/71636) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Support CAST and ALTER between JSON types with different parameters. [#72303](https://github.com/ClickHouse/ClickHouse/pull/72303) ([Pavel Kruglov](https://github.com/Avogar)).
* Support equal comparison for values of JSON column. [#72991](https://github.com/ClickHouse/ClickHouse/pull/72991) ([Pavel Kruglov](https://github.com/Avogar)).
* Improve formatting of identifiers with JSON subcolumns to avoid unnecessary back quotes. [#73085](https://github.com/ClickHouse/ClickHouse/pull/73085) ([Pavel Kruglov](https://github.com/Avogar)).
* Interactive metrics improvements. Fix metrics from parallel replicas not being fully displayed. Display the metrics in order of the most recent update, then lexicographically by name. Do not display stale metrics. [#71631](https://github.com/ClickHouse/ClickHouse/pull/71631) ([Julia Kartseva](https://github.com/jkartseva)).
* Make JSON output format pretty by default. Add new setting `output_format_json_pretty_print` to control it and enable it by default. [#72148](https://github.com/ClickHouse/ClickHouse/pull/72148) ([Pavel Kruglov](https://github.com/Avogar)).
* Allow `LowCardinality(UUID)` by default. This has proven practical among ClickHouse Cloud customers. [#73826](https://github.com/ClickHouse/ClickHouse/pull/73826) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Better message during installation. [#73827](https://github.com/ClickHouse/ClickHouse/pull/73827) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Better message about password reset for ClickHouse Cloud. [#73831](https://github.com/ClickHouse/ClickHouse/pull/73831) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Improve the error message with a File table that cannot perform appends into a file. [#73832](https://github.com/ClickHouse/ClickHouse/pull/73832) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Ask when a user accidentally requests to output binary format (such as Native, Parquet, Avro) in the terminal. This closes [#59524](https://github.com/ClickHouse/ClickHouse/issues/59524). [#73833](https://github.com/ClickHouse/ClickHouse/pull/73833) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Highlight trailing spaces in Pretty and Vertical formats in the terminal for better clarity. This is controlled with the `output_format_pretty_highlight_trailing_spaces` setting. Initial implementation by [Braden Burns](https://github.com/bradenburns) from [#72996](https://github.com/ClickHouse/ClickHouse/issues/72996). Closes [#71590](https://github.com/ClickHouse/ClickHouse/issues/71590). [#73847](https://github.com/ClickHouse/ClickHouse/pull/73847) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* `clickhouse-client` and `clickhouse-local` will autodetect compression of stdin when it is redirected from a file. This closes [#70865](https://github.com/ClickHouse/ClickHouse/issues/70865). [#73848](https://github.com/ClickHouse/ClickHouse/pull/73848) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Cut too long column names in pretty formats by default. This is controlled by the `output_format_pretty_max_column_name_width_cut_to` and `output_format_pretty_max_column_name_width_min_chars_to_cut` settings. This is the continuation of the work of [tanmaydatta](https://github.com/tanmaydatta) in [#66502](https://github.com/ClickHouse/ClickHouse/issues/66502). This closes [#65968](https://github.com/ClickHouse/ClickHouse/issues/65968). [#73851](https://github.com/ClickHouse/ClickHouse/pull/73851) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Make `Pretty` formats prettier: squash blocks if not much time passed since the output of the previous block. This is controlled by new settings `output_format_pretty_squash_consecutive_ms` (50 ms by default) and `output_format_pretty_squash_max_wait_ms` (1000 ms by default). Continuation of [#49537](https://github.com/ClickHouse/ClickHouse/issues/49537). This closes [#49153](https://github.com/ClickHouse/ClickHouse/issues/49153). [#73852](https://github.com/ClickHouse/ClickHouse/pull/73852) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add a metric on the number of currently merging source parts. This closes [#70809](https://github.com/ClickHouse/ClickHouse/issues/70809). [#73868](https://github.com/ClickHouse/ClickHouse/pull/73868) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Highlight columns in the `Vertical` format if the output is to a terminal. This can be disabled with the `output_format_pretty_color` setting. [#73898](https://github.com/ClickHouse/ClickHouse/pull/73898) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Enhanced the MySQL compatibility to a level that now, `mysqlsh` (a rich MySQL CLI from Oracle) can connect to ClickHouse. This is needed to facilitate testing. [#73912](https://github.com/ClickHouse/ClickHouse/pull/73912) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Pretty formats can render multi-line fields inside a table cell, which improves readability. This is enabled by default and can be controlled by the setting `output_format_pretty_multiline_fields`. Continuation of the work by [Volodyachan](https://github.com/Volodyachan) in [#64094](https://github.com/ClickHouse/ClickHouse/issues/64094). This closes [#56912](https://github.com/ClickHouse/ClickHouse/issues/56912). [#74032](https://github.com/ClickHouse/ClickHouse/pull/74032) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Expose X-ClickHouse HTTP headers to JavaScript in the browser. It makes writing applications more convenient. [#74180](https://github.com/ClickHouse/ClickHouse/pull/74180) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* The `JSONEachRowWithProgress` format will include events with metadata, as well as totals and extremes. It also includes `rows_before_limit_at_least` and `rows_before_aggregation`. The format prints the exception properly if it arrives after partial results. The progress now includes elapsed nanoseconds. One final progress event is emitted at the end. The progress during query runtime will be printed no more frequently than the value of the `interactive_delay` setting. [#74181](https://github.com/ClickHouse/ClickHouse/pull/74181) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Hourglass will rotate smoothly in Play UI. [#74182](https://github.com/ClickHouse/ClickHouse/pull/74182) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Even if the HTTP response is compressed, send packets as soon as they arrive. This allows the browser to receive progress packets and compressed data. [#74201](https://github.com/ClickHouse/ClickHouse/pull/74201) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* If the number of output records is larger than N = `output_format_pretty_max_rows`, instead of displaying only the first N rows, we will cut the output table in the middle, displaying N/2 first rows and N/2 last rows. Continuation of [#64200](https://github.com/ClickHouse/ClickHouse/issues/64200). This closes [#59502](https://github.com/ClickHouse/ClickHouse/issues/59502). [#73929](https://github.com/ClickHouse/ClickHouse/pull/73929) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Allow more general join planning algorithm when hash join algorithm is enabled. [#71926](https://github.com/ClickHouse/ClickHouse/pull/71926) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Allow to create bloom\_filter index on columns with data type `DateTime64`. [#66416](https://github.com/ClickHouse/ClickHouse/pull/66416) ([Yutong Xiao](https://github.com/YutSean)).
* When `min_age_to_force_merge_seconds` and `min_age_to_force_merge_on_partition_only` are both enabled, the part merging will ignore the max bytes limit. [#73656](https://github.com/ClickHouse/ClickHouse/pull/73656) ([Kai Zhu](https://github.com/nauu)).
* Added HTTP headers to OpenTelemetry span logs table for enhanced traceability. [#70516](https://github.com/ClickHouse/ClickHouse/pull/70516) ([jonymohajanGmail](https://github.com/jonymohajanGmail)).
* Support writing `orc` file by custom time zone, not always by the `GMT` time zone. [#70615](https://github.com/ClickHouse/ClickHouse/pull/70615) ([kevinyhzou](https://github.com/KevinyhZou)).
* Respect IO scheduling settings when writing backups across clouds. [#71093](https://github.com/ClickHouse/ClickHouse/pull/71093) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
* Add `metric` column alias `name` to `system.asynchronous_metrics`. [#71164](https://github.com/ClickHouse/ClickHouse/pull/71164) ([megao](https://github.com/jetgm)).
* Historically for some reason, the query `ALTER TABLE MOVE PARTITION TO TABLE` checked `SELECT` and `ALTER DELETE` rights instead of dedicated `ALTER_MOVE_PARTITION`. This PR makes use of this access type. For compatibility, this permission is also will be granted implicitly if `SELECT` and `ALTER DELETE` are granted, but this behavior will be removed in future releases. Closes [#16403](https://github.com/ClickHouse/ClickHouse/issues/16403). [#71632](https://github.com/ClickHouse/ClickHouse/pull/71632) ([pufit](https://github.com/pufit)).
* Throw an exception when trying to materialize a column in the sort key instead of allowing it to break the sort order. [#71891](https://github.com/ClickHouse/ClickHouse/pull/71891) ([Peter Nguyen](https://github.com/petern48)).
* Hide secrets in `EXPLAIN QUERY TREE`. [#72025](https://github.com/ClickHouse/ClickHouse/pull/72025) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Support parquet integer logical types in the "native" reader. [#72105](https://github.com/ClickHouse/ClickHouse/pull/72105) ([Arthur Passos](https://github.com/arthurpassos)).
* Interactively request credentials in the browser if the default user requires a password. In previous versions, the server returned HTTP 403; now, it returns HTTP 401. [#72198](https://github.com/ClickHouse/ClickHouse/pull/72198) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Convert access types `CREATE_USER`, `ALTER_USER`, `DROP_USER`, `CREATE_ROLE`, `ALTER_ROLE`, `DROP_ROLE` from global to parameterized. That means you can now grant access management grants more precise:. [#72246](https://github.com/ClickHouse/ClickHouse/pull/72246) ([pufit](https://github.com/pufit)).
* Add the `latest_fail_error_code_name` column to `system.mutations`. We need this column to introduce a new metric on stuck mutations and use it to build graphs of the errors encountered in the cloud as well as, optionally, adding a new less-noisy alert. [#72398](https://github.com/ClickHouse/ClickHouse/pull/72398) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Reduce amount of allocation in the `ATTACH PARTITION` query. [#72583](https://github.com/ClickHouse/ClickHouse/pull/72583) ([Konstantin Morozov](https://github.com/k-morozov)).
* Make `max_bytes_before_external_sort` limit depends on total query memory consumption (previously it was number of bytes in the sorting block for one sorting thread, now it has the same meaning as `max_bytes_before_external_group_by` - it is total limit for the whole query memory for all threads). Also one more setting added to control on disk block size - `min_external_sort_block_bytes`. [#72598](https://github.com/ClickHouse/ClickHouse/pull/72598) ([Azat Khuzhin](https://github.com/azat)).
* Ignore memory restrictions by trace collector. [#72606](https://github.com/ClickHouse/ClickHouse/pull/72606) ([Azat Khuzhin](https://github.com/azat)).
* Add server settings `dictionaries_lazy_load` and `wait_dictionaries_load_at_startup` to `system.server_settings`. [#72664](https://github.com/ClickHouse/ClickHouse/pull/72664) ([Christoph Wurm](https://github.com/cwurm)).
* Adds setting `max_backup_bandwidth` to the list of settings that can be specified as part of `BACKUP`/`RESTORE` queries. [#72665](https://github.com/ClickHouse/ClickHouse/pull/72665) ([Christoph Wurm](https://github.com/cwurm)).
* Reducing the log level for appearing replicated parts in the ReplicatedMergeTree engine to help minimize the volume of logs generated in a replicated cluster. [#72876](https://github.com/ClickHouse/ClickHouse/pull/72876) ([mor-akamai](https://github.com/morkalfon)).
* Improve extraction of common expression in disjunctions. Allow simplifying the resulting filter expression even if there's no common subexpression for all the disjuncts. Continuation of [#71537](https://github.com/ClickHouse/ClickHouse/issues/71537). [#73271](https://github.com/ClickHouse/ClickHouse/pull/73271) ([Dmitry Novik](https://github.com/novikd)).
* In Storage `S3Queue`/`AzureQueue` allow to add settings where table was created without settings. [#73283](https://github.com/ClickHouse/ClickHouse/pull/73283) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Introduce a setting `least_greatest_legacy_null_behavior` (default: `false`) which controls if functions `least` and `greatest` handle `NULL` arguments by unconditionally returning `NULL` (if `true`) or by ignoring them (if `false`). [#73344](https://github.com/ClickHouse/ClickHouse/pull/73344) ([Robert Schulze](https://github.com/rschu1ze)).
* Use Keeper multi requests in the cleanup thread of ObjectStorageQueueMetadata. [#73357](https://github.com/ClickHouse/ClickHouse/pull/73357) ([Antonio Andelic](https://github.com/antonio2368)).
* When ClickHouse runs under a cgroup we will still collect system-wide asynchronous metrics related to system load, process scheduling, memory etc. They might provide useful signals when ClickHouse is the only process on the host with high resource consumption. [#73369](https://github.com/ClickHouse/ClickHouse/pull/73369) ([Nikita Taranov](https://github.com/nickitat)).
* In storage `S3Queue` allow to transfer old ordered tables created before 24.6 to new structure with buckets. [#73467](https://github.com/ClickHouse/ClickHouse/pull/73467) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Add `system.azure_queue` similar to existing `system.s3queue`. [#73477](https://github.com/ClickHouse/ClickHouse/pull/73477) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Function `parseDateTime64` (and its variants) now produces correct results for input dates before 1970 / after 2106. Example: `SELECT parseDateTime64InJodaSyntax('2200-01-01 00:00:00.000', 'yyyy-MM-dd HH:mm:ss.SSS')`. [#73594](https://github.com/ClickHouse/ClickHouse/pull/73594) ([zhanglistar](https://github.com/zhanglistar)).
* Address some `clickhouse-disks` usability issues addressed by users. Closes [#67136](https://github.com/ClickHouse/ClickHouse/issues/67136). [#73616](https://github.com/ClickHouse/ClickHouse/pull/73616) ([Daniil Ivanik](https://github.com/divanik)).
* Allow to alter commit settings in storage S3(Azure)Queue. (Commit settings are: `max_processed_files_before_commit`, `max_processed_rows_before_commit`, `max_processed_bytes_before_commit`, `max_processing_time_sec_before_commit`). [#73635](https://github.com/ClickHouse/ClickHouse/pull/73635) ([Kseniia Sumarokova](https://github.com/kssenii)).
* In storage S3(Azure)Queue aggregate progress between sources to compare with commit limit settings. [#73641](https://github.com/ClickHouse/ClickHouse/pull/73641) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Support core settings in `BACKUP`/`RESTORE` query. [#73650](https://github.com/ClickHouse/ClickHouse/pull/73650) ([Vitaly Baranov](https://github.com/vitlibar)).
* Take into account the `output_format_compression_level` on Parquet output. [#73651](https://github.com/ClickHouse/ClickHouse/pull/73651) ([Arthur Passos](https://github.com/arthurpassos)).
* Adds reading Apache Arrow's `fixed_size_list` as an `Array` instead of treating it as an unsupported type. [#73654](https://github.com/ClickHouse/ClickHouse/pull/73654) ([Julian Meyers](https://github.com/J-Meyers)).
* Add two backup engines: `Memory` (keeps backups inside the current user session), and `Null` (don't keep backups anywhere), which is for testing. [#73690](https://github.com/ClickHouse/ClickHouse/pull/73690) ([Vitaly Baranov](https://github.com/vitlibar)).
* `concurrent_threads_soft_limit_num` and `concurrent_threads_soft_limit_num_ratio_to_cores` could be changed w/o restart of a server. [#73713](https://github.com/ClickHouse/ClickHouse/pull/73713) ([Sergei Trifonov](https://github.com/serxa)).
* Add support for extended numeric types (`Decimal`, big integers) in `formatReadable` functions. [#73765](https://github.com/ClickHouse/ClickHouse/pull/73765) ([Raúl Marín](https://github.com/Algunenano)).
* Support TLS for Postgres wire protocol compatibility. [#73812](https://github.com/ClickHouse/ClickHouse/pull/73812) ([scanhex12](https://github.com/scanhex12)).
* The function `isIPv4String` returned true if the correct IPv4 address was followed by a zero byte, while it should return false in this case. Continuation of [#65387](https://github.com/ClickHouse/ClickHouse/issues/65387). [#73946](https://github.com/ClickHouse/ClickHouse/pull/73946) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Make the error code in the MySQL wire protocol compatible with MySQL. Continuation of [#56831](https://github.com/ClickHouse/ClickHouse/issues/56831). Closes [#50957](https://github.com/ClickHouse/ClickHouse/issues/50957). [#73948](https://github.com/ClickHouse/ClickHouse/pull/73948) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add setting `validate_enum_literals_in_opearators` to validate enum literals in operators like `IN`, `NOT IN` against the enum type and throw an exception if the literal is not a valid enum value. [#73985](https://github.com/ClickHouse/ClickHouse/pull/73985) ([Vladimir Cherkasov](https://github.com/vdimir)).
* In Storage `S3(Azure)Queue` commit all files (in a single butch defined by commit settings) in a single keeper transaction. [#73991](https://github.com/ClickHouse/ClickHouse/pull/73991) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Disable header detection for executable UDFs and dictionaries (could lead to Function 'X': wrong result, expected Y row(s), actual Y-1). [#73992](https://github.com/ClickHouse/ClickHouse/pull/73992) ([Azat Khuzhin](https://github.com/azat)).
* Add the `distributed` option for `EXPLAIN PLAN.` Now, `EXPLAIN distributed=1 ... ` appends remote plan to `ReadFromParallelRemote*` steps. [#73994](https://github.com/ClickHouse/ClickHouse/pull/73994) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Use correct return type for not/xor with Dynamic arguments. [#74013](https://github.com/ClickHouse/ClickHouse/pull/74013) ([Pavel Kruglov](https://github.com/Avogar)).
* Allow changing `add_implicit_sign_column_constraint_for_collapsing_engine` after table creation. [#74014](https://github.com/ClickHouse/ClickHouse/pull/74014) ([Christoph Wurm](https://github.com/cwurm)).
* Support subcolumns in materialized view select query. [#74030](https://github.com/ClickHouse/ClickHouse/pull/74030) ([Pavel Kruglov](https://github.com/Avogar)).
* There are now three simple ways to set a custom prompt in `clickhouse-client`: 1. via command-line parameter `--prompt`, 2. in the configuration file, via settings `[...]`, and 3. also in the configuration file, via per-connection settings `[...]`. [#74168](https://github.com/ClickHouse/ClickHouse/pull/74168) ([Christoph Wurm](https://github.com/cwurm)).
* Autodetect secure connection based on connecting to port 9440 in ClickHouse Client. [#74212](https://github.com/ClickHouse/ClickHouse/pull/74212) ([Christoph Wurm](https://github.com/cwurm)).
* Authenticate users with username only for http\_handlers (previously it requires user to put the password as well). [#74221](https://github.com/ClickHouse/ClickHouse/pull/74221) ([Azat Khuzhin](https://github.com/azat)).
* Support for the alternative query languages PRQL and KQL was marked experimental. To use them, specify settings `allow_experimental_prql_dialect = 1` and `allow_experimental_kusto_dialect = 1`. [#74224](https://github.com/ClickHouse/ClickHouse/pull/74224) ([Robert Schulze](https://github.com/rschu1ze)).
* Support returning the default Enum type in more aggregate functions. [#74272](https://github.com/ClickHouse/ClickHouse/pull/74272) ([Raúl Marín](https://github.com/Algunenano)).
* In `OPTIMIZE TABLE`, it is now possible to specify keyword `FORCE` as an alternative to existing keyword `FINAL`. [#74342](https://github.com/ClickHouse/ClickHouse/pull/74342) ([Robert Schulze](https://github.com/rschu1ze)).
* Add the `IsServerShuttingDown` metric, which is needed to trigger an alert when the server shutdown takes too much time. [#74429](https://github.com/ClickHouse/ClickHouse/pull/74429) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
* Added Iceberg tables names to EXPLAIN. [#74485](https://github.com/ClickHouse/ClickHouse/pull/74485) ([alekseev-maksim](https://github.com/alekseev-maksim)).
* Provide a better error message when using RECURSIVE CTE with the old analyzer. [#74523](https://github.com/ClickHouse/ClickHouse/pull/74523) ([Raúl Marín](https://github.com/Algunenano)).
* Show extended error messages in `system.errors`. [#74574](https://github.com/ClickHouse/ClickHouse/pull/74574) ([Vitaly Baranov](https://github.com/vitlibar)).
* Allow to use password for client communication with clickhouse-keeper. This feature is not very useful if you specify proper SSL configuration for server and client, but still can be useful for some cases. Password cannot be longer than 16 characters. It's not connected with Keeper Auth model. [#74673](https://github.com/ClickHouse/ClickHouse/pull/74673) ([alesapin](https://github.com/alesapin)).
* Add error code for config reloader. [#74746](https://github.com/ClickHouse/ClickHouse/pull/74746) ([Garrett Thomas](https://github.com/garrettthomaskth)).
* Added support for IPv6 addresses in MySQL and PostgreSQL table functions and engines. [#74796](https://github.com/ClickHouse/ClickHouse/pull/74796) ([Mikhail Koviazin](https://github.com/mkmkme)).
* Implement short circuit optimization for `divideDecimal`. Fixes [#74280](https://github.com/ClickHouse/ClickHouse/issues/74280). [#74843](https://github.com/ClickHouse/ClickHouse/pull/74843) ([Kevin Mingtarja](https://github.com/kevinmingtarja)).
* Now users can be specified inside the startup scripts. [#74894](https://github.com/ClickHouse/ClickHouse/pull/74894) ([pufit](https://github.com/pufit)).
* Add support for Azure SAS Tokens. [#72959](https://github.com/ClickHouse/ClickHouse/pull/72959) ([Azat Khuzhin](https://github.com/azat)).
#### Bug Fix (user-visible misbehavior in an official stable release)
* Set parquet compression level only if compression codec supports it. [#74659](https://github.com/ClickHouse/ClickHouse/pull/74659) ([Arthur Passos](https://github.com/arthurpassos)).
* Fixed a regression that using collation locales with modifiers throws an error. As an example, `SELECT arrayJoin(['kk 50', 'KK 01', ' KK 2', ' KK 3', 'kk 1', 'x9y99', 'x9y100']) item ORDER BY item ASC COLLATE 'tr-u-kn-true-ka-shifted` now works. [#73544](https://github.com/ClickHouse/ClickHouse/pull/73544) ([Robert Schulze](https://github.com/rschu1ze)).
* Fix cannot create SEQUENTIAL node with keeper-client. [#64177](https://github.com/ClickHouse/ClickHouse/pull/64177) ([Duc Canh Le](https://github.com/canhld94)).
* Fix incorrect character counting in the position functions. [#71003](https://github.com/ClickHouse/ClickHouse/pull/71003) ([思维](https://github.com/heymind)).
* `RESTORE` operations for access entities required more permission than necessary because of unhandled partial revokes. This PR fixes the issue. Closes [#71853](https://github.com/ClickHouse/ClickHouse/issues/71853). [#71958](https://github.com/ClickHouse/ClickHouse/pull/71958) ([pufit](https://github.com/pufit)).
* Avoid pause after `ALTER TABLE REPLACE/MOVE PARTITION FROM/TO TABLE`. Retrieve correct settings for background task scheduling. [#72024](https://github.com/ClickHouse/ClickHouse/pull/72024) ([Aleksei Filatov](https://github.com/aalexfvk)).
* Fix handling of empty tuples in some input and output formats (e.g. Parquet, Arrow). [#72616](https://github.com/ClickHouse/ClickHouse/pull/72616) ([Michael Kolupaev](https://github.com/al13n321)).
* Column-level GRANT SELECT/INSERT statements on wildcard databases/tables now throw an error. [#72646](https://github.com/ClickHouse/ClickHouse/pull/72646) ([Johann Gan](https://github.com/johanngan)).
* Fix the situation when a user can't run `REVOKE ALL ON *.*` because of implicit grants in the target access entity. [#72872](https://github.com/ClickHouse/ClickHouse/pull/72872) ([pufit](https://github.com/pufit)).
* Fix positive timezone formatting of formatDateTime scalar function. [#73091](https://github.com/ClickHouse/ClickHouse/pull/73091) ([ollidraese](https://github.com/ollidraese)).
* Fix to correctly reflect source port when connection made through PROXYv1 and `auth_use_forwarded_address` is set - previously proxy port was incorrectly used. Add `currentQueryID()` function. [#73095](https://github.com/ClickHouse/ClickHouse/pull/73095) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Propagate format settings to NativeWriter in TCPHandler, so settings like `output_format_native_write_json_as_string` are applied correctly. [#73179](https://github.com/ClickHouse/ClickHouse/pull/73179) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix a crash in StorageObjectStorageQueue. [#73274](https://github.com/ClickHouse/ClickHouse/pull/73274) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix rare crash in refreshable materialized view during server shutdown. [#73323](https://github.com/ClickHouse/ClickHouse/pull/73323) ([Michael Kolupaev](https://github.com/al13n321)).
* The `%f` placeholder of function `formatDateTime` now unconditionally generates six (sub-second) digits. This makes the behavior compatible with MySQL `DATE_FORMAT` function. The previous behavior can be restored using setting `formatdatetime_f_prints_scale_number_of_digits = 1`. [#73324](https://github.com/ClickHouse/ClickHouse/pull/73324) ([ollidraese](https://github.com/ollidraese)).
* Fixed filtering by `_etag` column while reading from `s3` storage and table function. [#73353](https://github.com/ClickHouse/ClickHouse/pull/73353) ([Anton Popov](https://github.com/CurtizJ)).
* Fix `Not-ready Set is passed as the second argument for function 'in'` error when `IN (subquery)` is used in `JOIN ON` expression, with the old analyzer. [#73382](https://github.com/ClickHouse/ClickHouse/pull/73382) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fix preparing for squashin for Dynamic and JSON columns. Previously in some cases new types could be inserted into shared variant/shared data even when the limit on types/paths is not reached. [#73388](https://github.com/ClickHouse/ClickHouse/pull/73388) ([Pavel Kruglov](https://github.com/Avogar)).
* Check for corrupted sizes during types binary decoding to avoid too big allocations. [#73390](https://github.com/ClickHouse/ClickHouse/pull/73390) ([Pavel Kruglov](https://github.com/Avogar)).
* Fixed a logical error when reading from single-replica cluster with parallel replicas enabled. [#73403](https://github.com/ClickHouse/ClickHouse/pull/73403) ([Michael Kolupaev](https://github.com/al13n321)).
* Fix ObjectStorageQueue with ZooKeeper and older Keeper. [#73420](https://github.com/ClickHouse/ClickHouse/pull/73420) ([Antonio Andelic](https://github.com/antonio2368)).
* Implements fix, needed to enable hive partitioning by default. [#73479](https://github.com/ClickHouse/ClickHouse/pull/73479) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Fix data race when creating vector similarity index. [#73517](https://github.com/ClickHouse/ClickHouse/pull/73517) ([Antonio Andelic](https://github.com/antonio2368)).
* Fixes segfault when the source of the dictionary contains a function with wrong data. [#73535](https://github.com/ClickHouse/ClickHouse/pull/73535) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Fix retries on failed insert in storage S3(Azure)Queue. Closes [#70951](https://github.com/ClickHouse/ClickHouse/issues/70951). [#73546](https://github.com/ClickHouse/ClickHouse/pull/73546) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fixed error in function `tupleElement` which may appear in some cases for tuples with `LowCardinality` elements and enabled setting `optimize_functions_to_subcolumns`. [#73548](https://github.com/ClickHouse/ClickHouse/pull/73548) ([Anton Popov](https://github.com/CurtizJ)).
* Fix parsing enum glob followed by range one. Fixes [#73473](https://github.com/ClickHouse/ClickHouse/issues/73473). [#73569](https://github.com/ClickHouse/ClickHouse/pull/73569) ([Konstantin Bogdanov](https://github.com/thevar1able)).
* Fixed parallel\_replicas\_for\_non\_replicated\_merge\_tree being ignored in subqueries for non-replicated tables. [#73584](https://github.com/ClickHouse/ClickHouse/pull/73584) ([Igor Nikonov](https://github.com/devcrafter)).
* Fix for std::logical\_error thrown when task cannot be scheduled. Found in stress tests. [#73629](https://github.com/ClickHouse/ClickHouse/pull/73629) ([Alexander Gololobov](https://github.com/davenger)).
* Do not interpret queries in `EXPLAIN SYNTAX` to avoid logical errors with incorrect processing stage for distributed queries. Fixes [#65205](https://github.com/ClickHouse/ClickHouse/issues/65205). [#73634](https://github.com/ClickHouse/ClickHouse/pull/73634) ([Dmitry Novik](https://github.com/novikd)).
* Fix possible data inconsistency in Dynamic column. Fixes possible logical error `Nested columns sizes are inconsistent with local_discriminators column size`. [#73644](https://github.com/ClickHouse/ClickHouse/pull/73644) ([Pavel Kruglov](https://github.com/Avogar)).
* Fixed `NOT_FOUND_COLUMN_IN_BLOCK` in queries with `FINAL` and `SAMPLE`. Fixed incorrect result in selects with `FINAL` from `CollapsingMergeTree` and enabled optimizations of `FINAL` . [#73682](https://github.com/ClickHouse/ClickHouse/pull/73682) ([Anton Popov](https://github.com/CurtizJ)).
* Fix crash in LIMIT BY COLUMNS. [#73686](https://github.com/ClickHouse/ClickHouse/pull/73686) ([Raúl Marín](https://github.com/Algunenano)).
* Fix the bug when the normal projection is forced to use, and query is exactly the same as the projection defined, but the projection is not selected and thus error is prompted. [#73700](https://github.com/ClickHouse/ClickHouse/pull/73700) ([Shichao Jin](https://github.com/jsc0218)).
* Fix deserialization of Dynamic/Object structure. It could lead to CANNOT\_READ\_ALL\_DATA exceptions. [#73767](https://github.com/ClickHouse/ClickHouse/pull/73767) ([Pavel Kruglov](https://github.com/Avogar)).
* Skip `metadata_version.txt` in while restoring parts from a backup. [#73768](https://github.com/ClickHouse/ClickHouse/pull/73768) ([Vitaly Baranov](https://github.com/vitlibar)).
* Fix segmentation fault when Casting to Enum with LIKE. [#73775](https://github.com/ClickHouse/ClickHouse/pull/73775) ([zhanglistar](https://github.com/zhanglistar)).
* Fix for S3 Express bucket not working as disk. [#73777](https://github.com/ClickHouse/ClickHouse/pull/73777) ([Sameer Tamsekar](https://github.com/stamsekar)).
* Allow merging of rows with invalid sign column values in CollapsingMergeTree tables. [#73864](https://github.com/ClickHouse/ClickHouse/pull/73864) ([Christoph Wurm](https://github.com/cwurm)).
* Fix getting error when querying ddl with offline replica. [#73876](https://github.com/ClickHouse/ClickHouse/pull/73876) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Fixes occasional failure to compare `map()` types due to possibility to create `Map` lacking explicit naming ('keys','values') of its nested tuple. [#73878](https://github.com/ClickHouse/ClickHouse/pull/73878) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Ignore window functions during GROUP BY ALL clause resolution. Fix [#73501](https://github.com/ClickHouse/ClickHouse/issues/73501). [#73916](https://github.com/ClickHouse/ClickHouse/pull/73916) ([Dmitry Novik](https://github.com/novikd)).
* Fix implicit privileges (worked as wildcard before). [#73932](https://github.com/ClickHouse/ClickHouse/pull/73932) ([Azat Khuzhin](https://github.com/azat)).
* Fix high memory usage during nested Maps creation. [#73982](https://github.com/ClickHouse/ClickHouse/pull/73982) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix parsing nested JSON with empty keys. [#73993](https://github.com/ClickHouse/ClickHouse/pull/73993) ([Pavel Kruglov](https://github.com/Avogar)).
* Fix: alias can be not added to the projection if it is referenced by another alias and selected in inverse order. [#74033](https://github.com/ClickHouse/ClickHouse/pull/74033) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Ignore object not found errors for Azure during plain\_rewritable disk initialization. [#74059](https://github.com/ClickHouse/ClickHouse/pull/74059) ([Julia Kartseva](https://github.com/jkartseva)).
* Fix behaviour of `any` and `anyLast` with enum types and empty table. [#74061](https://github.com/ClickHouse/ClickHouse/pull/74061) ([Joanna Hulboj](https://github.com/jh0x)).
* Fixes case when the user specifies keyword arguments in the kafka table engine. [#74064](https://github.com/ClickHouse/ClickHouse/pull/74064) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Fix altering Storage `S3Queue` settings with "s3queue\_" prefix to without and vice versa. [#74075](https://github.com/ClickHouse/ClickHouse/pull/74075) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Add a setting `allow_push_predicate_ast_for_distributed_subqueries`. This adds AST-based predicate push-down for distributed queries with the analyzer. This is a temporary solution that we use until distributed queries with query plan serialization are supported. Closes [#66878](https://github.com/ClickHouse/ClickHouse/issues/66878) [#69472](https://github.com/ClickHouse/ClickHouse/issues/69472) [#65638](https://github.com/ClickHouse/ClickHouse/issues/65638) [#68030](https://github.com/ClickHouse/ClickHouse/issues/68030) [#73718](https://github.com/ClickHouse/ClickHouse/issues/73718). [#74085](https://github.com/ClickHouse/ClickHouse/pull/74085) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fixes issue when after [#73095](https://github.com/ClickHouse/ClickHouse/issues/73095) port can be present in the forwarded\_for field, which leads to inability to resolve host name with port included. [#74116](https://github.com/ClickHouse/ClickHouse/pull/74116) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
* Fixed incorrect formatting of `ALTER TABLE (DROP STATISTICS ...) (DROP STATISTICS ...)`. [#74126](https://github.com/ClickHouse/ClickHouse/pull/74126) ([Han Fei](https://github.com/hanfei1991)).
* Fix for issue [#66112](https://github.com/ClickHouse/ClickHouse/issues/66112). [#74128](https://github.com/ClickHouse/ClickHouse/pull/74128) ([Anton Ivashkin](https://github.com/ianton-ru)).
* It is no longer possible to use `Loop` as a table engine in `CREATE TABLE`. This combination was previously causing segfaults. [#74137](https://github.com/ClickHouse/ClickHouse/pull/74137) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
* Fix security issue to prevent SQL injection in postgresql and sqlite table functions. [#74144](https://github.com/ClickHouse/ClickHouse/pull/74144) ([Pablo Marcos](https://github.com/pamarcos)).
* Fix crash when reading a subcolumn from the compressed Memory engine table. Fixes [#74009](https://github.com/ClickHouse/ClickHouse/issues/74009). [#74161](https://github.com/ClickHouse/ClickHouse/pull/74161) ([Nikita Taranov](https://github.com/nickitat)).
* Fixed an infinite loop occurring with queries to the system.detached\_tables. [#74190](https://github.com/ClickHouse/ClickHouse/pull/74190) ([Konstantin Morozov](https://github.com/k-morozov)).
* Fix logical error in s3queue during setting file as failed. [#74216](https://github.com/ClickHouse/ClickHouse/pull/74216) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix native copy settings (`allow_s3_native_copy`/`allow_azure_native_copy`) for `RESTORE` from base backup. [#74286](https://github.com/ClickHouse/ClickHouse/pull/74286) ([Azat Khuzhin](https://github.com/azat)).
* Fixed the issue when the number of detached tables in the database is a multiple of max\_block\_size. [#74289](https://github.com/ClickHouse/ClickHouse/pull/74289) ([Konstantin Morozov](https://github.com/k-morozov)).
* Fix copying via ObjectStorage (i.e. S3) when source and destination credentials differs. [#74331](https://github.com/ClickHouse/ClickHouse/pull/74331) ([Azat Khuzhin](https://github.com/azat)).
* Fix detection of "use the Rewrite method in the JSON API" for native copy on GCS. [#74338](https://github.com/ClickHouse/ClickHouse/pull/74338) ([Azat Khuzhin](https://github.com/azat)).
* Fix incorrect calculation of `BackgroundMergesAndMutationsPoolSize` (it was x2 from real value). [#74509](https://github.com/ClickHouse/ClickHouse/pull/74509) ([alesapin](https://github.com/alesapin)).
* Fix the bug of leaking keeper watches when enable Cluster Discovery. [#74521](https://github.com/ClickHouse/ClickHouse/pull/74521) ([RinChanNOW](https://github.com/RinChanNOWWW)).
* Fix mem alignment issue reported by UBSan [#74512](https://github.com/ClickHouse/ClickHouse/issues/74512). [#74534](https://github.com/ClickHouse/ClickHouse/pull/74534) ([Arthur Passos](https://github.com/arthurpassos)).
* Fix KeeperMap concurrent cleanup during table creation. [#74568](https://github.com/ClickHouse/ClickHouse/pull/74568) ([Antonio Andelic](https://github.com/antonio2368)).
* Do not remove unused projection columns in subqueries in the presence of `EXCEPT` or `INTERSECT` to preserve the correct query result. Fixes [#73930](https://github.com/ClickHouse/ClickHouse/issues/73930). Fixes [#66465](https://github.com/ClickHouse/ClickHouse/issues/66465). [#74577](https://github.com/ClickHouse/ClickHouse/pull/74577) ([Dmitry Novik](https://github.com/novikd)).
* Fixed `INSERT SELECT` queries between tables with `Tuple` columns and enabled sparse serialization. [#74698](https://github.com/ClickHouse/ClickHouse/pull/74698) ([Anton Popov](https://github.com/CurtizJ)).
* Function `right` works incorrectly for const negative offset. [#74701](https://github.com/ClickHouse/ClickHouse/pull/74701) ([Daniil Ivanik](https://github.com/divanik)).
* Fix insertion of gzip-ed data sometimes fails due to flawed decompression on client side. [#74707](https://github.com/ClickHouse/ClickHouse/pull/74707) ([siyuan](https://github.com/linkwk7)).
* Partial revokes with wildcard grants could remove more privileges than expected. Closes [#74263](https://github.com/ClickHouse/ClickHouse/issues/74263). [#74751](https://github.com/ClickHouse/ClickHouse/pull/74751) ([pufit](https://github.com/pufit)).
* Keeper fix: fix reading log entries from disk. [#74785](https://github.com/ClickHouse/ClickHouse/pull/74785) ([Antonio Andelic](https://github.com/antonio2368)).
* Fixed checking grants for SYSTEM REFRESH/START/STOP VIEW, now it's not required to have this grant on `*.*` to execute a query for a specific view, only grant for this view are required. [#74789](https://github.com/ClickHouse/ClickHouse/pull/74789) ([Alexander Tokmakov](https://github.com/tavplubix)).
* The `hasColumnInTable` function doesn't account for alias columns. Fix it to also work for alias columns. [#74841](https://github.com/ClickHouse/ClickHouse/pull/74841) ([Bharat Nallan](https://github.com/bharatnc)).
* Fix FILE\_DOESNT\_EXIST error occurring during data parts merge for a table with an empty column in Azure Blob Storage. [#74892](https://github.com/ClickHouse/ClickHouse/pull/74892) ([Julia Kartseva](https://github.com/jkartseva)).
* Fix projection column name when joining temporary tables, close [#68872](https://github.com/ClickHouse/ClickHouse/issues/68872). [#74897](https://github.com/ClickHouse/ClickHouse/pull/74897) ([Vladimir Cherkasov](https://github.com/vdimir)).
#### Build/Testing/Packaging Improvement
* The universal installation script will propose installation even on macOS. [#74339](https://github.com/ClickHouse/ClickHouse/pull/74339) ([Alexey Milovidov](https://github.com/alexey-milovidov)).