### ClickHouse release v21.9.3.30-stable FIXME as compared to v21.9.2.17-stable

#### Improvement
* Backported in [#28897](https://github.com/ClickHouse/ClickHouse/issues/28897): Use real tmp file instead of predefined "rows_sources" for vertical merges. This avoids generating garbage directories in tmp disks. [#28299](https://github.com/ClickHouse/ClickHouse/pull/28299) ([Amos Bird](https://github.com/amosbird)).

#### Bug Fix (user-visible misbehaviour in official stable or prestable release)

* Backported in [#28815](https://github.com/ClickHouse/ClickHouse/issues/28815): Fix possible crash for `SELECT` with partially created aggregate projection in case of exception. [#28700](https://github.com/ClickHouse/ClickHouse/pull/28700) ([Amos Bird](https://github.com/amosbird)).
* Backported in [#28789](https://github.com/ClickHouse/ClickHouse/issues/28789): Fix benign race condition in ReplicatedMergeTreeQueue. Shouldn't be visible for user, but can lead to subtle bugs. [#28734](https://github.com/ClickHouse/ClickHouse/pull/28734) ([alesapin](https://github.com/alesapin)).
* Backported in [#28842](https://github.com/ClickHouse/ClickHouse/issues/28842): Fix expressions compilation with short circuit evaluation. [#28821](https://github.com/ClickHouse/ClickHouse/pull/28821) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#28993](https://github.com/ClickHouse/ClickHouse/issues/28993): Fixed a race condition between `DROP PART` and `REPLACE/MOVE PARTITION` that might cause replicas to diverge in rare cases. [#28864](https://github.com/ClickHouse/ClickHouse/pull/28864) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Backported in [#28949](https://github.com/ClickHouse/ClickHouse/issues/28949): Fix reading of subcolumns from compact parts. [#28873](https://github.com/ClickHouse/ClickHouse/pull/28873) ([Anton Popov](https://github.com/CurtizJ)).
* Backported in [#28925](https://github.com/ClickHouse/ClickHouse/issues/28925): Fix bug with LowCardinality in short-curcuit function evaluation. Closes [#28884](https://github.com/ClickHouse/ClickHouse/issues/28884). [#28887](https://github.com/ClickHouse/ClickHouse/pull/28887) ([Kruglov Pavel](https://github.com/Avogar)).
* Backported in [#28927](https://github.com/ClickHouse/ClickHouse/issues/28927): Fix higher-order array functions (`SIGSEGV` for `arrayCompact`/`ILLEGAL_COLUMN` for `arrayDifference`/`arrayCumSumNonNegative`) with consts. [#28904](https://github.com/ClickHouse/ClickHouse/pull/28904) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#29025](https://github.com/ClickHouse/ClickHouse/issues/29025): Fix the number of threads used in `GLOBAL IN` subquery (it was executed in single threads since [#19414](https://github.com/ClickHouse/ClickHouse/issues/19414) bugfix). [#28997](https://github.com/ClickHouse/ClickHouse/pull/28997) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).