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sidebar_position: 1
sidebar_label: 2025
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# 2025 Changelog

### ClickHouse release v25.4.11.15-stable (d384a0dd98b) FIXME as compared to v25.4.10.45-stable (e9923e54d62)

#### Improvement
* Backported in [#83633](https://github.com/ClickHouse/ClickHouse/issues/83633): 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)).

#### Bug Fix (user-visible misbehavior in an official stable release)
* Backported in [#83570](https://github.com/ClickHouse/ClickHouse/issues/83570): 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)).
* Backported in [#83670](https://github.com/ClickHouse/ClickHouse/issues/83670): Fix incorrect memory around max_untracked_memory. [#83607](https://github.com/ClickHouse/ClickHouse/pull/83607) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#83661](https://github.com/ClickHouse/ClickHouse/issues/83661): 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)).
* Backported in [#83741](https://github.com/ClickHouse/ClickHouse/issues/83741): Fix endless loop in estimateCompressionRatio() with block_size_bytes=0. [#83704](https://github.com/ClickHouse/ClickHouse/pull/83704) ([Azat Khuzhin](https://github.com/azat)).

#### Build/Testing/Packaging Improvement
* Backported in [#83649](https://github.com/ClickHouse/ClickHouse/issues/83649): Apply fix for CVE-2025-6375 in Poco from upstream. [#82647](https://github.com/ClickHouse/ClickHouse/pull/82647) ([Konstantin Bogdanov](https://github.com/thevar1able)).

#### NOT FOR CHANGELOG / INSIGNIFICANT

* Backported in [#83567](https://github.com/ClickHouse/ClickHouse/issues/83567): Bring back `--pre-pull` command to the integration tests jobs, it was deleted in [#73291](https://github.com/ClickHouse/ClickHouse/issues/73291). [#83528](https://github.com/ClickHouse/ClickHouse/pull/83528) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).

