ClickHouse/docs/changelogs/v20.10.3.30-stable.md

ClickHouse release v20.10.3.30-stable FIXME as compared to v20.10.2.20-stable

Improvement

• Backported in #16313: Add allow_nondeterministic_optimize_skip_unused_shards (to allow non deterministic like rand() or dictGet() in sharding key). #16105 (Azat Khuzhin).

Bug Fix

• Backported in #16202: Decrement the ReadonlyReplica metric when detaching read-only tables. This fixes #15598. #15592 (sundyli).
• Backported in #16177: Possibility to move part to another disk/volume if the first attempt was failed. #15723 (Pavel Kovalenko).
• Backported in #16323: Fixed DROP TABLE IF EXISTS failure with Table ... doesn't exist error when table is concurrently renamed (for Atomic database engine). Fixed rare deadlock when concurrently executing some DDL queries with multiple tables (like DROP DATABASE and RENAME TABLE) Fixed DROP/DETACH DATABASE failure with Table ... doesn't exist when concurrently executing DROP/DETACH TABLE. #15934 (Alexander Tokmakov).
• Backported in #16359: Fix collate name & charset name parser and support length = 0 for string type. #16008 (Winter Zhang).
• Backported in #16299: Fix dictGet in sharding_key (and similar places, i.e. when the function context is stored permanently). #16205 (Azat Khuzhin).
• Backported in #16234: Fix the case when memory can be overallocated regardless to the limit. This closes #14560. #16206 (Alexey Milovidov).
• Backported in #16327: Fix a possible memory leak during GROUP BY with string keys, caused by an error in TwoLevelStringHashTable implementation. #16264 (Amos Bird).
• Backported in #16374: Fix async Distributed INSERT w/ prefer_localhost_replica=0 and internal_replication. #16358 (Azat Khuzhin).
• Backported in #16419: Fix group by with totals/rollup/cube modifers and min/max functions over group by keys. Fixes #16393. #16397 (Anton Popov).
• Backported in #16448: Fix double free in case of exception in function dictGet. It could have happened if dictionary was loaded with error. #16429 (Nikolai Kochetov).