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sidebar_position: 1
sidebar_label: 2025
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# 2025 Changelog

### ClickHouse release v25.4.4.25-stable (c97f6ffeac6) FIXME as compared to v25.4.3.22-stable (f23535c7722)

#### Bug Fix (user-visible misbehavior in an official stable release)
* Backported in [#79981](https://github.com/ClickHouse/ClickHouse/issues/79981): Fix deserialization of variant discriminators with basic format in compact parts. It was introduced in https://github.com/ClickHouse/ClickHouse/pull/55518. [#79000](https://github.com/ClickHouse/ClickHouse/pull/79000) ([Pavel Kruglov](https://github.com/Avogar)).
* Backported in [#79715](https://github.com/ClickHouse/ClickHouse/issues/79715): Fix using incorrect paths when renaming an Atomic database. [#79569](https://github.com/ClickHouse/ClickHouse/pull/79569) ([Tuan Pham Anh](https://github.com/tuanpach)).
* Backported in [#80049](https://github.com/ClickHouse/ClickHouse/issues/80049): 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)).
* Backported in [#80113](https://github.com/ClickHouse/ClickHouse/issues/80113): 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)).
* Backported in [#80078](https://github.com/ClickHouse/ClickHouse/issues/80078): 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)).
* Backported in [#80185](https://github.com/ClickHouse/ClickHouse/issues/80185): 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)).

#### NOT FOR CHANGELOG / INSIGNIFICANT

* Backported in [#79811](https://github.com/ClickHouse/ClickHouse/issues/79811): Better introspection for index analysis performance. [#79347](https://github.com/ClickHouse/ClickHouse/pull/79347) ([Nikita Taranov](https://github.com/nickitat)).
* Backported in [#80222](https://github.com/ClickHouse/ClickHouse/issues/80222): Make test_check_replicated_does_not_block_shutdown less flaky and faster. [#79552](https://github.com/ClickHouse/ClickHouse/pull/79552) ([Raúl Marín](https://github.com/Algunenano)).
* Backported in [#80099](https://github.com/ClickHouse/ClickHouse/issues/80099): `enable_user_name_access_type` must not affect `DEFINER` access type. [#80026](https://github.com/ClickHouse/ClickHouse/pull/80026) ([pufit](https://github.com/pufit)).
* Backported in [#80202](https://github.com/ClickHouse/ClickHouse/issues/80202): Disable CPU overload checks for all tests. [#80166](https://github.com/ClickHouse/ClickHouse/pull/80166) ([Alexander Gololobov](https://github.com/davenger)).
* Backported in [#80230](https://github.com/ClickHouse/ClickHouse/issues/80230): Disable CPU overload check in server settings by default. [#80211](https://github.com/ClickHouse/ClickHouse/pull/80211) ([Alexander Gololobov](https://github.com/davenger)).

