Project: ClickHouse (App Definition and Development / Database)
File: v20.8.19.4-stable.md

Backported in : If tuple of NULLs, e.g. `(NULL, NULL)` is on the left hand side of `IN` operator with tuples of non-NULLs on the right hand side, e.g. `SELECT (NULL, NULL) IN ((0, 0), (3, 1))` return 0 instead of throwing an exception about incompatible types. The expression may also appear due to optimization of something like `SELECT (NULL, NULL) = (8, 0) OR (NULL, NULL) = (3, 2) OR (NULL, NULL) = (0, 0) OR (NULL, NULL) = (3, 1)`. This closes . (). Backported in : Fixed very rare race condition on background cleanup of old blocks. It might cause a block not to be deduplicated if it's too close to the end of deduplication window. (). Backported in : Fixed `Cannot unlink file` error on unsuccessful creation of ReplicatedMergeTree table with multidisk configuration. This closes . (). Backported in : When modify column's default value without datatype, and this column is used as ReplacingMergeTree's parameter like column `b` in the below example, then the server will core dump: ``` CREATE TABLE altertest (a Int32, b DateTime) ENGINE = ReplacingMergeTree(b) ORDER BY a; ALTER TABLE altertest MODIFY COLUMN `b` DEFAULT now(); ``` the sever throw error: ``` 2021.04.22 09:48:00.685317 (). Backported in : Fix `columns` function when multiple joins in select query. Closes . (). Backported in : Fix misinterpretation of some `LIKE` expressions with escape sequences. (). Backported in : Fixed a bug in recovery of staled `ReplicatedMergeTree` replica. Some metadata updates could be ignored by staled replica if `ALTER` query was executed during downtime of the replica. (). Backported in : Fix SIGSEGV for external GROUP BY and overflow row (i.e. queries like `SELECT FROM GROUP BY WITH TOTALS SETTINGS maxbytesbeforeexternalgroupby>0, maxrowstogroupby>0, groupbyoverflowmode='any', totalsmode='beforehaving'`). (). Backported in : Fix crash in MergeJoin, close . (). Backported in : Fix race condition which could happen in RBAC under a heavy load. This PR fixes , ,. (). Backported in : Fixed a bug in moving Materialized View from Ordinary to Atomic database (`RENAME TABLE` query). Now inner table is moved to new database together with Materialized View. Fixes . (). Backported in : - Fixed the deadlock that can happen during LDAP role (re)mapping, when LDAP group is mapped to a nonexistent local role. (). Backported in : Fix incorrect monotonicity of toWeek function. This fixes . This bug was introduced in https://github.com/ClickHouse/ClickHouse/pull/5212 , and was exposed later by smarter partition pruner. (). Backported in : Fixed the behavior when query `SYSTEM RESTART REPLICA` or `SYSTEM SYNC REPLICA` is being processed infinitely. This was detected on server with extremely little amount of RAM. (). Backported in : Fix bug when exception `Mutation was killed` can be thrown to the client on mutation wait when mutation not loaded into memory yet. (). Backported in : Fixed bug with declaring S3 disk at root of bucket. Earlier, it reported an error: ``` (). Backported in : Fix possible heap-buffer-overflow in Arrow. (). Backported in : Fix crash in query with cross join and `joinedsubqueryrequires_alias = 0`. Fixes . (). Backported in : Fix TOCTOU error in installation script. (). Backported in : Fix Logical Error Cannot sum Array/Tuple in min/maxMap. (). Backported in : Fix segfault when sharding_key is absent in task config for copier. (). Backported in : Fixed `No such file or directory` error on moving `Distributed` table between databases. Fixes . (). Backported in : Fix possible crash in `pointInPolygon` if the setting `validate_polygons` is turned off. ().