ClickHouse/docs/changelogs/v20.12.6.29-stable.md

ClickHouse release v20.12.6.29-stable FIXME as compared to v20.12.5.18-stable

Bug Fix

• Backported in #19984: Background thread which executes ON CLUSTER queries might hang waiting for dropped replicated table to do something. It's fixed. #19684 (yiguolei).
• Backported in #20240: Fix a bug that moving pieces to destination table may failed in case of launching multiple clickhouse-copiers. #19743 (madianjun).
• Backported in #20080: Fix starting the server with tables having default expressions containing dictGet(). Allow getting return type of dictGet() without loading dictionary. #19805 (Vitaly Baranov).
• Backported in #20298: * Bugfix in StorageJoin. #20079 (Vladimir C).
• Backported in #20391: The MongoDB table engine now establishes connection only when it's going to read data. ATTACH TABLE won't try to connect anymore. #20110 (Vitaly Baranov).
• Backported in #20328: Fix rare server crash on config reload during the shutdown. Fixes #19689. #20224 (alesapin).
• Backported in #20332: Restrict to DROP or RENAME version column of *CollapsingMergeTree and ReplacingMergeTree table engines. #20300 (alesapin).
• Backported in #20364: Fix too often retries of failed background tasks for ReplicatedMergeTree table engines family. This could lead to too verbose logging and increased CPU load. Fixes #20203. #20335 (alesapin).
• Backported in #20377: Fix null dereference with join_use_nulls=1. #20344 (Azat Khuzhin).
• Backported in #20360: Avoid invalid dereference in RANGE_HASHED() dictionary. #20345 (Azat Khuzhin).

NO CL ENTRY

• NO CL ENTRY: 'Revert "Backport #20224 to 20.12: Fix access control manager destruction order"'. #20396 (alesapin).