2025 Changelog

ClickHouse release v25.4.10.45-stable (e9923e54d62) FIXME as compared to v25.4.9.14-stable (5ca9638860e)

Performance Improvement

• Backported in #83339: Try to speedup QueryTreeHash a bit. #82617 (Nikolai Kochetov).

Improvement

• Backported in #83013: 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 (Antonio Andelic).
• Backported in #83203: SYSTEM RESTART REPLICA may fail due to ZooKeeper connection issues. To avoid forgetting about this table, we now retry until the table is created. #82616 (Nikolay Degterinsky).
• Backported in #83180: Consolidate unknown settings warnings in clickhouse client and log them as a summary. #83042 (Bharat Nallan).

Bug Fix (user-visible misbehavior in an official stable release)

• Backported in #83315: Fix "Context has expired" for Iceberg. #82146 (Azat Khuzhin).
• Backported in #83255: Fix disabling boundary alignment for cached buffer in external table engines. It was broken in https://github.com/ClickHouse/ClickHouse/pull/81868. #82493 (Kseniia Sumarokova).
• Backported in #82911: 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 (Smita Kulkarni).
• Backported in #83110: Fix exception safety in union/intersect/except_default_mode rewrite. Closes #82664. #82820 (Alexey Milovidov).
• Backported in #83328: Fix data races in Iceberg. #82841 (Azat Khuzhin).
• Backported in #83287: Set salt for auth data when parsing from AST with type SCRAM_SHA256_PASSWORD. #82888 (Tuan Pham Anh).
• Backported in #83025: Fix filter modification for queries with a JOIN expression with a table with storage Merge. Fixes #82092. #82950 (Dmitry Novik).
• Backported in #83309: Fix LOGICAL_ERROR in QueryMetricLog: Mutex cannot be NULL. #82979 (Pablo Marcos).
• Backported in #83238: Fix performance degradation with the enabled analyzer when secondary queries always read all columns from the VIEWs. Fixes #81718. #83036 (Dmitry Novik).
• Backported in #83428: Fix misleading error message when restoring a backup on a read-only disk. #83051 (Julia Kartseva).
• Backported in #83197: 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. #83077 (Pavel Kruglov).
• Backported in #83403: 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 (Antonio Andelic).
• Backported in #83465: Fix TOO_DEEP_SUBQUERIES exception when CTE definition references another table expression with the same name. #83413 (Dmitry Novik).

Build/Testing/Packaging Improvement

• Backported in #83535: Use expat 2.7.1 inside Poco. #82661 (Konstantin Bogdanov).

NOT FOR CHANGELOG / INSIGNIFICANT

• Backported in #83250: Cache metadata json string in iceberg metadata. #81429 (Han Fei).
• Backported in #82756: Add a setting to preserve old behaviour of dateTrunc function. #82530 (Pavel Kruglov).