2023 Changelog

- The `BACKUP` command will not decrypt data from encrypted disks while making a backup. Instead the data will be stored in a backup in encrypted form. Such backups can be restored only to an encrypted disk with the same (or extended) list of encryption keys. [#48896](https://github.com/ClickHouse/ClickHouse/pull/48896) ([Vitaly Baranov](https://github.com/vitlibar)).
- Added possibility to use temporary tables in FROM part of ATTACH PARTITION FROM and REPLACE PARTITION FROM. [#49436](https://github.com/ClickHouse/ClickHouse/pull/49436) ([Roman Vasin](https://github.com/rvasin)).
- Added setting `async_insert` for `MergeTree` tables. It has the same meaning as query-level setting `async_insert` and enables asynchronous inserts for specific table. Note: it doesn't take effect for insert queries from `clickhouse-client`, use query-level setting in that case. [#49122](https://github.com/ClickHouse/ClickHouse/pull/49122) ([Anton Popov](https://github.com/CurtizJ)).
- Add support for size suffixes in quota creation statement parameters. [#49087](https://github.com/ClickHouse/ClickHouse/pull/49087) ([Eridanus](https://github.com/Eridanus117)).
- Extend `first_value` and `last_value` to accept NULL. [#46467](https://github.com/ClickHouse/ClickHouse/pull/46467) ([lgbo](https://github.com/lgbo-ustc)).
- Add alias `str_to_map` and `mapFromString` for `extractKeyValuePairs`. closes <https://github.com/clickhouse/clickhouse/issues/47185>. [#49466](https://github.com/ClickHouse/ClickHouse/pull/49466) ([flynn](https://github.com/ucasfl)).
- Add support for CGroup version 2 for asynchronous metrics about the memory usage and availability. This closes [#37983](https://github.com/ClickHouse/ClickHouse/issues/37983). [#45999](https://github.com/ClickHouse/ClickHouse/pull/45999) ([sichenzhao](https://github.com/sichenzhao)).
- Cluster table functions should always skip unavailable shards. close [#46314](https://github.com/ClickHouse/ClickHouse/issues/46314). [#46765](https://github.com/ClickHouse/ClickHouse/pull/46765) ([zk\_kiger](https://github.com/zk-kiger)).
- Allow CSV file to contain empty columns in its header. [#47496](https://github.com/ClickHouse/ClickHouse/pull/47496) ([你不要过来啊](https://github.com/iiiuwioajdks)).
- Add Google Cloud Storage S3 compatible table function `gcs`. Like the `oss` and `cosn` functions, it is just an alias over the `s3` table function, and it does not bring any new features. [#47815](https://github.com/ClickHouse/ClickHouse/pull/47815) ([Kuba Kaflik](https://github.com/jkaflik)).
- Add ability to use strict parts size for S3 (compatibility with CloudFlare R2 S3 Storage). [#48492](https://github.com/ClickHouse/ClickHouse/pull/48492) ([Azat Khuzhin](https://github.com/azat)).
- Added new columns with info about `Replicated` database replicas to `system.clusters`: `database_shard_name`, `database_replica_name`, `is_active`. Added an optional `FROM SHARD` clause to `SYSTEM DROP DATABASE REPLICA` query. [#48548](https://github.com/ClickHouse/ClickHouse/pull/48548) ([Alexander Tokmakov](https://github.com/tavplubix)).
- Add a new column `zookeeper_name` in system.replicas, to indicate on which (auxiliary) zookeeper cluster the replicated table's metadata is stored. [#48549](https://github.com/ClickHouse/ClickHouse/pull/48549) ([cangyin](https://github.com/cangyin)).
- `IN` operator support the comparison of `Date` and `Date32`. Closes [#48736](https://github.com/ClickHouse/ClickHouse/issues/48736). [#48806](https://github.com/ClickHouse/ClickHouse/pull/48806) ([flynn](https://github.com/ucasfl)).
- Support for erasure codes in `HDFS`, author: @M1eyu2018, @tomscut. [#48833](https://github.com/ClickHouse/ClickHouse/pull/48833) ([M1eyu](https://github.com/M1eyu2018)).
- Implement SYSTEM DROP REPLICA from auxiliary ZooKeeper clusters, may be close [#48931](https://github.com/ClickHouse/ClickHouse/issues/48931). [#48932](https://github.com/ClickHouse/ClickHouse/pull/48932) ([wangxiaobo](https://github.com/wzb5212)).
- Add Array data type to MongoDB. Closes [#48598](https://github.com/ClickHouse/ClickHouse/issues/48598). [#48983](https://github.com/ClickHouse/ClickHouse/pull/48983) ([Nikolay Degterinsky](https://github.com/evillique)).
- Support storing `Interval` data types in tables. [#49085](https://github.com/ClickHouse/ClickHouse/pull/49085) ([larryluogit](https://github.com/larryluogit)).
- Allow using `ntile` window function without explicit window frame definition: `ntile(3) OVER (ORDER BY a)`, close [#46763](https://github.com/ClickHouse/ClickHouse/issues/46763). [#49093](https://github.com/ClickHouse/ClickHouse/pull/49093) ([vdimir](https://github.com/vdimir)).
- Added settings (`number_of_mutations_to_delay`, `number_of_mutations_to_throw`) to delay or throw `ALTER` queries that create mutations (`ALTER UPDATE`, `ALTER DELETE`, `ALTER MODIFY COLUMN`, ...) in case when table already has a lot of unfinished mutations. [#49117](https://github.com/ClickHouse/ClickHouse/pull/49117) ([Anton Popov](https://github.com/CurtizJ)).
- Catch exception from `create_directories` in filesystem cache. [#49203](https://github.com/ClickHouse/ClickHouse/pull/49203) ([Kseniia Sumarokova](https://github.com/kssenii)).
- Copies embedded examples to a new field `example` in `system.functions` to supplement the field `description`. [#49222](https://github.com/ClickHouse/ClickHouse/pull/49222) ([Dan Roscigno](https://github.com/DanRoscigno)).
- Enable connection options for the MongoDB dictionary. Example: `xml <source> <mongodb> <host>localhost</host> <port>27017</port> <user></user> <password></password> <db>test</db> <collection>dictionary_source</collection> <options>ssl=true</options> </mongodb> </source>` ### Documentation entry for user-facing changes. [#49225](https://github.com/ClickHouse/ClickHouse/pull/49225) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
- Added an alias `asymptotic` for `asymp` computational method for `kolmogorovSmirnovTest`. Improved documentation. [#49286](https://github.com/ClickHouse/ClickHouse/pull/49286) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
- Aggregation function groupBitAnd/Or/Xor now work on signed integer data. This makes them consistent with the behavior of scalar functions bitAnd/Or/Xor. [#49292](https://github.com/ClickHouse/ClickHouse/pull/49292) ([exmy](https://github.com/exmy)).
- Split function-documentation into more fine-granular fields. [#49300](https://github.com/ClickHouse/ClickHouse/pull/49300) ([Robert Schulze](https://github.com/rschu1ze)).
- Use multiple threads shared between all tables within a server to load outdated data parts. The the size of the pool and its queue is controlled by `max_outdated_parts_loading_thread_pool_size` and `outdated_part_loading_thread_pool_queue_size` settings. [#49317](https://github.com/ClickHouse/ClickHouse/pull/49317) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
- Don't overestimate the size of processed data for `LowCardinality` columns when they share dictionaries between blocks. This closes [#49322](https://github.com/ClickHouse/ClickHouse/issues/49322). See also [#48745](https://github.com/ClickHouse/ClickHouse/issues/48745). [#49323](https://github.com/ClickHouse/ClickHouse/pull/49323) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
- Parquet writer now uses reasonable row group size when invoked through `OUTFILE`. [#49325](https://github.com/ClickHouse/ClickHouse/pull/49325) ([Michael Kolupaev](https://github.com/al13n321)).
- Allow restricted keywords like `ARRAY` as an alias if the alias is quoted. Closes [#49324](https://github.com/ClickHouse/ClickHouse/issues/49324). [#49360](https://github.com/ClickHouse/ClickHouse/pull/49360) ([Nikolay Degterinsky](https://github.com/evillique)).