2025 Changelog

- 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>. [#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)).