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sidebar_label: 2022
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# 2022 Changelog

### ClickHouse release v21.3.18.4-lts FIXME as compared to v21.3.17.2-lts

#### Improvement
* Backported in [#30355](https://github.com/ClickHouse/ClickHouse/issues/30355): Use separate `clickhouse-bridge` group and user for bridge processes. Set oom_score_adj so the bridges will be first subjects for OOM killer. Set set maximum RSS to 1 GiB. Closes [#23861](https://github.com/ClickHouse/ClickHouse/issues/23861). [#25280](https://github.com/ClickHouse/ClickHouse/pull/25280) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Backported in [#29945](https://github.com/ClickHouse/ClickHouse/issues/29945): Update zoneinfo files to 2021c. [#29925](https://github.com/ClickHouse/ClickHouse/pull/29925) ([Alexey Milovidov](https://github.com/alexey-milovidov)).

#### Bug Fix
* Backported in [#30041](https://github.com/ClickHouse/ClickHouse/issues/30041): Fix shutdown of `AccessControlManager`. Now there can't be reloading of the configuration after AccessControlManager has been destroyed. This PR fixes the flaky test [test_user_directories/test.py::test_relative_path](https://clickhouse-test-reports.s3.yandex.net/0/f0e3122507ed8bea3f177495531c7d56bcb32466/integration_tests_(thread).html). [#29951](https://github.com/ClickHouse/ClickHouse/pull/29951) ([Vitaly Baranov](https://github.com/vitlibar)).

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

* Backported in [#29260](https://github.com/ClickHouse/ClickHouse/issues/29260): Fix invalid constant type conversion when nullable or lowcardinality primary key is used. [#28636](https://github.com/ClickHouse/ClickHouse/pull/28636) ([Amos Bird](https://github.com/amosbird)).
* Backported in [#29026](https://github.com/ClickHouse/ClickHouse/issues/29026): 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)).
* Backported in [#29194](https://github.com/ClickHouse/ClickHouse/issues/29194): Fix segfault while inserting into column with type LowCardinality(Nullable) in Avro input format. [#29132](https://github.com/ClickHouse/ClickHouse/pull/29132) ([Kruglov Pavel](https://github.com/Avogar)).
* Backported in [#29360](https://github.com/ClickHouse/ClickHouse/issues/29360): Fix possible `Table columns structure in ZooKeeper is different from local table structure` exception while recreating or creating new replicas of `ReplicatedMergeTree`, when one of table columns have default expressions with case-insensitive functions. [#29266](https://github.com/ClickHouse/ClickHouse/pull/29266) ([Anton Popov](https://github.com/CurtizJ)).
* Backported in [#29300](https://github.com/ClickHouse/ClickHouse/issues/29300): Fix connection timeouts (`send_timeout`/`receive_timeout`). [#29282](https://github.com/ClickHouse/ClickHouse/pull/29282) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#30042](https://github.com/ClickHouse/ClickHouse/issues/30042): Condition in filter predicate could be lost after push-down optimisation. [#29625](https://github.com/ClickHouse/ClickHouse/pull/29625) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Backported in [#29848](https://github.com/ClickHouse/ClickHouse/issues/29848): Fix concurrent access to `LowCardinality` during `GROUP BY` (leads to SIGSEGV). [#29782](https://github.com/ClickHouse/ClickHouse/pull/29782) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#30066](https://github.com/ClickHouse/ClickHouse/issues/30066): Fix crash of sample by `tuple()`, closes [#30004](https://github.com/ClickHouse/ClickHouse/issues/30004). [#30016](https://github.com/ClickHouse/ClickHouse/pull/30016) ([flynn](https://github.com/ucasfl)).
* Backported in [#30332](https://github.com/ClickHouse/ClickHouse/issues/30332): * Allow identifiers staring with numbers in multiple joins. [#30230](https://github.com/ClickHouse/ClickHouse/pull/30230) ([Vladimir C](https://github.com/vdimir)).
* Backported in [#30379](https://github.com/ClickHouse/ClickHouse/issues/30379): fix replaceRegexpAll bug. [#30292](https://github.com/ClickHouse/ClickHouse/pull/30292) ([Memo](https://github.com/Joeywzr)).

#### NOT FOR CHANGELOG / INSIGNIFICANT

* Do not add const group by key for query with only having. [#28975](https://github.com/ClickHouse/ClickHouse/pull/28975) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Merging [#27963](https://github.com/ClickHouse/ClickHouse/issues/27963) [#29063](https://github.com/ClickHouse/ClickHouse/pull/29063) ([Maksim Kita](https://github.com/kitaisreal)).
* May be fix s3 tests [#29762](https://github.com/ClickHouse/ClickHouse/pull/29762) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Fix ca-bundle.crt in kerberized_hadoop/Dockerfile [#30358](https://github.com/ClickHouse/ClickHouse/pull/30358) ([Vladimir C](https://github.com/vdimir)).
