Changelog 2026

- `system.blob_storage_log` is now available for Azure Blob Storage. [#93105](https://github.com/ClickHouse/ClickHouse/pull/93105) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
- Implement `blob_storage_log` for Local and HDFS. Fix an error when `S3Queue` used something other than the disk name for logging in `blob_storage_log`. Add `error_code` column to `blob_storage_log`. Split the test configuration file to simplify local testing. [#93106](https://github.com/ClickHouse/ClickHouse/pull/93106) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
- `clickhouse-client` and `clickhouse-local` will highlight digit groups (thousands, millions, etc.) inside numeric literals while typing. This closes [#93100](https://github.com/ClickHouse/ClickHouse/issues/93100). [#93108](https://github.com/ClickHouse/ClickHouse/pull/93108) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
- Adds support in `clickhouse-client` for command-line arguments with a space surrounding the equals sign. Closes [#93077](https://github.com/ClickHouse/ClickHouse/issues/93077). [#93174](https://github.com/ClickHouse/ClickHouse/pull/93174) ([Cole Smith](https://github.com/colesmith54)).
- With `<interactive_history_legacy_keymap>true</interactive_history_legacy_keymap>`, the CLI client can now fall back to Ctrl-R for regular search like before, while Ctrl-T does fuzzy search. [#87785](https://github.com/ClickHouse/ClickHouse/pull/87785) ([Larry Snizek](https://github.com/larry-cdn77)).
- The statement to clear caches `SYSTEM DROP [...] CACHE` gave the false impression that the statement disables the cache. ClickHouse now supports statement `SYSTEM CLEAR [...] CACHE` which is more obvious. The old syntax remains available. [#93727](https://github.com/ClickHouse/ClickHouse/pull/93727) ([Pranav Tiwari](https://github.com/pranavt84)).
- Support multiple columns as primary key in `EmbeddedRocksDB`. Closes [#32819](https://github.com/ClickHouse/ClickHouse/issues/32819). [#33917](https://github.com/ClickHouse/ClickHouse/pull/33917) ([usurai](https://github.com/usurai)).
- It is now possible to use non-constant IN for scalars (queries like `val1 NOT IN if(cond, val2, val3)`). [#93495](https://github.com/ClickHouse/ClickHouse/pull/93495) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
- Prevent `x-amz-server-side-encryption` headers from being propagated to `HeadObject`, `UploadPart` & `CompleteMultipartUpload` S3 requests as they're not supported. [#64577](https://github.com/ClickHouse/ClickHouse/pull/64577) ([Francisco J. Jurado Moreno](https://github.com/Beetelbrox)).
- Tracking hive partitioning for ordered mode in S3Queue. Resolves [#71161](https://github.com/ClickHouse/ClickHouse/issues/71161). [#81040](https://github.com/ClickHouse/ClickHouse/pull/81040) ([Anton Ivashkin](https://github.com/ianton-ru)).
- Optimize space reservation in filesystem cache. `FileCache::collectCandidatesForEviction` will be executed without unique lock. [#82764](https://github.com/ClickHouse/ClickHouse/pull/82764) ([Kseniia Sumarokova](https://github.com/kssenii)).
- Support composite rotation strategy (size + time) for server log. [#87620](https://github.com/ClickHouse/ClickHouse/pull/87620) ([Jianmei Zhang](https://github.com/zhangjmruc)).
- CLI client can now specify `<warnings>false</warnings>` instead of the command line `--no-warnings`. [#87783](https://github.com/ClickHouse/ClickHouse/pull/87783) ([Larry Snizek](https://github.com/larry-cdn77)).
- Add support for the `avg` aggregate function with Date, DateTime and Time values as arguments. Closes [#82267](https://github.com/ClickHouse/ClickHouse/issues/82267). [#87845](https://github.com/ClickHouse/ClickHouse/pull/87845) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
- The optimization `use_join_disjunctions_push_down` is enabled by default. [#89313](https://github.com/ClickHouse/ClickHouse/pull/89313) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
- Support more table engines and data source kinds in the correlated subqueries. Closes [#80775](https://github.com/ClickHouse/ClickHouse/issues/80775). [#90175](https://github.com/ClickHouse/ClickHouse/pull/90175) ([Dmitry Novik](https://github.com/novikd)).
- If the schema of parameterized view is specified explicitly, it is shown. Close [#88875](https://github.com/ClickHouse/ClickHouse/issues/88875), [#81385](https://github.com/ClickHouse/ClickHouse/issues/81385). [#90220](https://github.com/ClickHouse/ClickHouse/pull/90220) ([Grigorii Sokolik](https://github.com/GSokol)).
- Correctly handle the gap in Keeper log entries if logs are before the last committed index. [#90403](https://github.com/ClickHouse/ClickHouse/pull/90403) ([Antonio Andelic](https://github.com/antonio2368)).
- Improve `min_free_disk_bytes_to_perform_insert` setting to work correctly with JBOD volumes. [#90878](https://github.com/ClickHouse/ClickHouse/pull/90878) ([Aleksandr Musorin](https://github.com/AVMusorin)).
- Make it possible to specify `storage_class_name` setting in named collections for `S3` table engine and `s3` table function. [#91926](https://github.com/ClickHouse/ClickHouse/pull/91926) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
- Support inserting auxiliary zookeeper by `system.zookeeper`. [#92092](https://github.com/ClickHouse/ClickHouse/pull/92092) ([RinChanNOW](https://github.com/RinChanNOWWW)).
- Add new metrics for the keeper: `KeeperChangelogWrittenBytes`, `KeeperChangelogFileSyncMicroseconds`, `KeeperSnapshotWrittenBytes` and `KeeperSnapshotFileSyncMicroseconds` profile events as well as `KeeperBatchSizeElements` and `KeeperBatchSizeBytes` histogram metrics. [#92149](https://github.com/ClickHouse/ClickHouse/pull/92149) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
- Add a new setting, `trace_profile_events_list`, which limits tracing with `trace_profile_event` to the specified list of event names. This allows more precise data collection on large workloads. [#92298](https://github.com/ClickHouse/ClickHouse/pull/92298) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
- Support SYSTEM NOTIFY FAILPOINT for pausable failpoints. - Support SYSTEM WAIT FAILPOINT fp PAUSE/RESUME. [#92368](https://github.com/ClickHouse/ClickHouse/pull/92368) ([Shaohua Wang](https://github.com/tiandiwonder)).
- Add `creation` (implicit/explicit) column to `system.data_skipping_indices`. [#92378](https://github.com/ClickHouse/ClickHouse/pull/92378) ([Raúl Marín](https://github.com/Algunenano)).
- Allow passing the description of columns for YTsaurus dyn tables to the dictionary source. [#92391](https://github.com/ClickHouse/ClickHouse/pull/92391) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
- In [#63985](https://github.com/ClickHouse/ClickHouse/pull/63985), we made it possible to specify all the parameters needed for TLS configuration on a per-port basis (see [composable protocols](https://clickhouse.com/docs/operations/settings/composable-protocols)), so we don't have to rely on global TLS config. However, the implementation still implicitly requires a global `openSSL.server` config section to exist, which conflicts with setups where different TLS configurations are needed for different ports. For example, in keeper-in-server deployments, we need separate TLS configs for inter-keeper communication and clickhouse client connections. [#92457](https://github.com/ClickHouse/ClickHouse/pull/92457) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
- Introduce a new setting `input_format_binary_max_type_complexity` that limits the total number of type nodes that can be decoded in binary format to prevent malicious payloads. [#92519](https://github.com/ClickHouse/ClickHouse/pull/92519) ([Raufs Dunamalijevs](https://github.com/rienath)).
- Reflect running tasks in `system.background_schedule_pool{,_log}`. Add documentation. [#92587](https://github.com/ClickHouse/ClickHouse/pull/92587) ([Azat Khuzhin](https://github.com/azat)).
- Execute current query in Ctrl+R search in client if no history match found. [#92749](https://github.com/ClickHouse/ClickHouse/pull/92749) ([Azat Khuzhin](https://github.com/azat)).