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### ClickHouse release v22.2, 2022-02-17. [Presentation](https://presentations.clickhouse.com/2022-release-22.2/), [Video](https://www.youtube.com/watch?v=6EG1gwhSTPg)[​](#a-id222a-clickhouse-release-v222-2022-02-17 "Direct link to a-id222a-clickhouse-release-v222-2022-02-17")

#### Upgrade Notes[​](#upgrade-notes-3 "Direct link to Upgrade Notes")

- Applying data skipping indexes for queries with FINAL may produce incorrect result. In this release we disabled data skipping indexes by default for queries with FINAL (a new setting `use_skip_indexes_if_final` is introduced and disabled by default). [#34243](https://github.com/ClickHouse/ClickHouse/pull/34243) ([Azat Khuzhin](https://github.com/azat)).

#### New Feature[​](#new-feature-10 "Direct link to New Feature")

- Projections are production ready. Set `allow_experimental_projection_optimization` by default and deprecate this setting. [#34456](https://github.com/ClickHouse/ClickHouse/pull/34456) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
- An option to create a new files on insert for `File`/`S3`/`HDFS` engines. Allow to overwrite a file in `HDFS`. Throw an exception in attempt to overwrite a file in `S3` by default. Throw an exception in attempt to append data to file in formats that have a suffix (and thus don't support appends, like `Parquet`, `ORC`). Closes [#31640](https://github.com/ClickHouse/ClickHouse/issues/31640) Closes [#31622](https://github.com/ClickHouse/ClickHouse/issues/31622) Closes [#23862](https://github.com/ClickHouse/ClickHouse/issues/23862) Closes [#15022](https://github.com/ClickHouse/ClickHouse/issues/15022) Closes [#16674](https://github.com/ClickHouse/ClickHouse/issues/16674). [#33302](https://github.com/ClickHouse/ClickHouse/pull/33302) ([Kruglov Pavel](https://github.com/Avogar)).
- Add a setting that allows a user to provide own deduplication semantic in `MergeTree`/`ReplicatedMergeTree` If provided, it's used instead of data digest to generate block ID. So, for example, by providing a unique value for the setting in each INSERT statement, the user can avoid the same inserted data being deduplicated. This closes: [#7461](https://github.com/ClickHouse/ClickHouse/issues/7461). [#32304](https://github.com/ClickHouse/ClickHouse/pull/32304) ([Igor Nikonov](https://github.com/devcrafter)).
- Add support of `DEFAULT` keyword for INSERT statements. Closes [#6331](https://github.com/ClickHouse/ClickHouse/issues/6331). [#33141](https://github.com/ClickHouse/ClickHouse/pull/33141) ([Andrii Buriachevskyi](https://github.com/1over)).
- `EPHEMERAL` column specifier is added to `CREATE TABLE` query. Closes [#9436](https://github.com/ClickHouse/ClickHouse/issues/9436). [#34424](https://github.com/ClickHouse/ClickHouse/pull/34424) ([yakov-olkhovskiy](https://github.com/yakov-olkhovskiy)).
- Support `IF EXISTS` clause for `TTL expr TO [DISK|VOLUME] [IF EXISTS] 'xxx'` feature. Parts will be moved to disk or volume only if it exists on replica, so `MOVE TTL` rules will be able to behave differently on replicas according to the existing storage policies. Resolves [#34455](https://github.com/ClickHouse/ClickHouse/issues/34455). [#34504](https://github.com/ClickHouse/ClickHouse/pull/34504) ([Anton Popov](https://github.com/CurtizJ)).
- Allow set default table engine and to create tables without specifying ENGINE. [#34187](https://github.com/ClickHouse/ClickHouse/pull/34187) ([Ilya Yatsishin](https://github.com/qoega)).
- Add table function `format(format_name, data)`. [#34125](https://github.com/ClickHouse/ClickHouse/pull/34125) ([Kruglov Pavel](https://github.com/Avogar)).
- Detect format in `clickhouse-local` by file name even in the case when it is passed to stdin. [#33829](https://github.com/ClickHouse/ClickHouse/pull/33829) ([Kruglov Pavel](https://github.com/Avogar)).
- Add schema inference for `values` table function. Closes [#33811](https://github.com/ClickHouse/ClickHouse/issues/33811). [#34017](https://github.com/ClickHouse/ClickHouse/pull/34017) ([Kruglov Pavel](https://github.com/Avogar)).
- Dynamic reload of server TLS certificates on config reload. Closes [#15764](https://github.com/ClickHouse/ClickHouse/issues/15764). [#15765](https://github.com/ClickHouse/ClickHouse/pull/15765) ([johnskopis](https://github.com/johnskopis)). [#31257](https://github.com/ClickHouse/ClickHouse/pull/31257) ([Filatenkov Artur](https://github.com/FArthur-cmd)).
- Now ReplicatedMergeTree can recover data when some of its disks are broken. [#13544](https://github.com/ClickHouse/ClickHouse/pull/13544) ([Amos Bird](https://github.com/amosbird)).
- Fault-tolerant connections in clickhouse-client: `clickhouse-client ... --host host1 --host host2 --port port2 --host host3 --port port --host host4`. [#34490](https://github.com/ClickHouse/ClickHouse/pull/34490) ([Kruglov Pavel](https://github.com/Avogar)). [#33824](https://github.com/ClickHouse/ClickHouse/pull/33824) ([Filippov Denis](https://github.com/DF5HSE)).
- Add `DEGREES` and `RADIANS` functions for MySQL compatibility. [#33769](https://github.com/ClickHouse/ClickHouse/pull/33769) ([Bharat Nallan](https://github.com/bharatnc)).
- Add `h3ToCenterChild` function. [#33313](https://github.com/ClickHouse/ClickHouse/pull/33313) ([Bharat Nallan](https://github.com/bharatnc)). Add new h3 miscellaneous functions: `edgeLengthKm`,`exactEdgeLengthKm`,`exactEdgeLengthM`,`exactEdgeLengthRads`,`numHexagons`. [#33621](https://github.com/ClickHouse/ClickHouse/pull/33621) ([Bharat Nallan](https://github.com/bharatnc)).
- Add function `bitSlice` to extract bit subsequences from String/FixedString. [#33360](https://github.com/ClickHouse/ClickHouse/pull/33360) ([RogerYK](https://github.com/RogerYK)).
- Implemented `meanZTest` aggregate function. [#33354](https://github.com/ClickHouse/ClickHouse/pull/33354) ([achimbab](https://github.com/achimbab)).
- Add confidence intervals to T-tests aggregate functions. [#33260](https://github.com/ClickHouse/ClickHouse/pull/33260) ([achimbab](https://github.com/achimbab)).
- Add function `addressToLineWithInlines`. Close [#26211](https://github.com/ClickHouse/ClickHouse/issues/26211). [#33467](https://github.com/ClickHouse/ClickHouse/pull/33467) ([SuperDJY](https://github.com/cmsxbc)).
- Added `#!` and `#`  as a recognised start of a single line comment. Closes [#34138](https://github.com/ClickHouse/ClickHouse/issues/34138). [#34230](https://github.com/ClickHouse/ClickHouse/pull/34230) ([Aaron Katz](https://github.com/aaronstephenkatz)).

#### Experimental Feature[​](#experimental-feature-9 "Direct link to Experimental Feature")