2023 Changelog

- The ClickHouse server now respects memory limits changed via cgroups when reloading its configuration. [#53455](https://github.com/ClickHouse/ClickHouse/pull/53455) ([Robert Schulze](https://github.com/rschu1ze)).
- Add ability to turn off flush of Distributed tables on `DETACH`, `DROP`, or server shutdown. [#53501](https://github.com/ClickHouse/ClickHouse/pull/53501) ([Azat Khuzhin](https://github.com/azat)).
- The `domainRFC` function now supports IPv6 in square brackets. [#53506](https://github.com/ClickHouse/ClickHouse/pull/53506) ([Chen768959](https://github.com/Chen768959)).
- Use longer timeout for S3 CopyObject requests, which are used in backups. [#53533](https://github.com/ClickHouse/ClickHouse/pull/53533) ([Michael Kolupaev](https://github.com/al13n321)).
- Added server setting `aggregate_function_group_array_max_element_size`. This setting is used to limit array size for `groupArray` function at serialization. The default value is `16777215`. [#53550](https://github.com/ClickHouse/ClickHouse/pull/53550) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
- `SCHEMA` was added as alias for `DATABASE` to improve MySQL compatibility. [#53587](https://github.com/ClickHouse/ClickHouse/pull/53587) ([Daniël van Eeden](https://github.com/dveeden)).
- Add asynchronous metrics about tables in the system database. For example, `TotalBytesOfMergeTreeTablesSystem`. This closes [#53603](https://github.com/ClickHouse/ClickHouse/issues/53603). [#53604](https://github.com/ClickHouse/ClickHouse/pull/53604) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
- SQL editor in the Play UI and Dashboard will not use Grammarly. [#53614](https://github.com/ClickHouse/ClickHouse/pull/53614) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
- As expert-level settings, it is now possible to (1) configure the size\_ratio (i.e. the relative size of the protected queue) of the [index] mark/uncompressed caches, (2) configure the cache policy of the index mark and index uncompressed caches. [#53657](https://github.com/ClickHouse/ClickHouse/pull/53657) ([Robert Schulze](https://github.com/rschu1ze)).
- Added client info validation to the query packet in TCPHandler. [#53673](https://github.com/ClickHouse/ClickHouse/pull/53673) ([Alexey Gerasimchuck](https://github.com/Demilivor)).
- Retry loading parts in case of network errors while interaction with Microsoft Azure. [#53750](https://github.com/ClickHouse/ClickHouse/pull/53750) ([SmitaRKulkarni](https://github.com/SmitaRKulkarni)).
- Stacktrace for exceptions, Materailized view exceptions are propagated. [#53766](https://github.com/ClickHouse/ClickHouse/pull/53766) ([Ilya Golshtein](https://github.com/ilejn)).
- If no hostname or port were specified, keeper client will try to search for a connection string in the ClickHouse's config.xml. [#53769](https://github.com/ClickHouse/ClickHouse/pull/53769) ([pufit](https://github.com/pufit)).
- Add profile event `PartsLockMicroseconds` which shows the amount of microseconds we hold the data parts lock in MergeTree table engine family. [#53797](https://github.com/ClickHouse/ClickHouse/pull/53797) ([alesapin](https://github.com/alesapin)).
- Make reconnect limit in RAFT limits configurable for keeper. This configuration can help to make keeper to rebuild connection with peers quicker if the current connection is broken. [#53817](https://github.com/ClickHouse/ClickHouse/pull/53817) ([Pengyuan Bian](https://github.com/bianpengyuan)).
- Ignore foreign keys in tables definition to improve compatibility with MySQL, so a user wouldn't need to rewrite his SQL of the foreign key part, ref [#53380](https://github.com/ClickHouse/ClickHouse/issues/53380). [#53864](https://github.com/ClickHouse/ClickHouse/pull/53864) ([jsc0218](https://github.com/jsc0218)).