2023 Changelog

- `system.asynchronous_metrics` now includes metrics "QueryCacheEntries" and "QueryCacheBytes" to inspect the query cache. [#52650](https://github.com/ClickHouse/ClickHouse/pull/52650) ([Robert Schulze](https://github.com/rschu1ze)).
- Added possibility to use `s3_storage_class` parameter in the `SETTINGS` clause of the `BACKUP` statement for backups to S3. [#52658](https://github.com/ClickHouse/ClickHouse/pull/52658) ([Roman Vasin](https://github.com/rvasin)).
- Add utility `print-backup-info.py` which parses a backup metadata file and prints information about the backup. [#52690](https://github.com/ClickHouse/ClickHouse/pull/52690) ([Vitaly Baranov](https://github.com/vitlibar)).
- Closes [#49510](https://github.com/ClickHouse/ClickHouse/issues/49510). Currently we have database and table names case-sensitive, but BI tools query `information_schema` sometimes in lowercase, sometimes in uppercase. For this reason we have `information_schema` database, containing lowercase tables, such as `information_schema.tables` and `INFORMATION_SCHEMA` database, containing uppercase tables, such as `INFORMATION_SCHEMA.TABLES`. But some tools are querying `INFORMATION_SCHEMA.tables` and `information_schema.TABLES`. The proposed solution is to duplicate both lowercase and uppercase tables in lowercase and uppercase `information_schema` database. [#52695](https://github.com/ClickHouse/ClickHouse/pull/52695) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
- Query`CHECK TABLE` has better performance and usability (sends progress updates, cancellable). [#52745](https://github.com/ClickHouse/ClickHouse/pull/52745) ([vdimir](https://github.com/vdimir)).
- Add support for `modulo`, `intDiv`, `intDivOrZero` for tuples by distributing them across tuple's elements. [#52758](https://github.com/ClickHouse/ClickHouse/pull/52758) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
- Search for default `yaml` and `yml` configs in clickhouse-client after `xml`. [#52767](https://github.com/ClickHouse/ClickHouse/pull/52767) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
- When merging into non-'clickhouse' rooted configuration, configs with different root node name just bypassed without exception. [#52770](https://github.com/ClickHouse/ClickHouse/pull/52770) ([Yakov Olkhovskiy](https://github.com/yakov-olkhovskiy)).
- Now it's possible to specify min (`memory_profiler_sample_min_allocation_size`) and max (`memory_profiler_sample_max_allocation_size`) size for allocations to be tracked with sampling memory profiler. [#52779](https://github.com/ClickHouse/ClickHouse/pull/52779) ([alesapin](https://github.com/alesapin)).
- Add `precise_float_parsing` setting to switch float parsing methods (fast/precise). [#52791](https://github.com/ClickHouse/ClickHouse/pull/52791) ([Andrey Zvonov](https://github.com/zvonand)).
- Use the same default paths for `clickhouse-keeper` (symlink) as for `clickhouse-keeper` (executable). [#52861](https://github.com/ClickHouse/ClickHouse/pull/52861) ([Vitaly Baranov](https://github.com/vitlibar)).
- Improve error message for table function `remote`. Closes [#40220](https://github.com/ClickHouse/ClickHouse/issues/40220). [#52959](https://github.com/ClickHouse/ClickHouse/pull/52959) ([jiyoungyoooo](https://github.com/jiyoungyoooo)).
- Added the possibility to specify custom storage policy in the `SETTINGS` clause of `RESTORE` queries. [#52970](https://github.com/ClickHouse/ClickHouse/pull/52970) ([Victor Krasnov](https://github.com/sirvickr)).
- Add the ability to throttle the S3 requests on backup operations (`BACKUP` and `RESTORE` commands now honor `s3_max_[get/put]_[rps/burst]`). [#52974](https://github.com/ClickHouse/ClickHouse/pull/52974) ([Daniel Pozo Escalona](https://github.com/danipozo)).
- Add settings to ignore ON CLUSTER clause in queries for management of replicated user-defined functions or access control entities with replicated storage. [#52975](https://github.com/ClickHouse/ClickHouse/pull/52975) ([Aleksei Filatov](https://github.com/aalexfvk)).
- EXPLAIN actions for JOIN step. [#53006](https://github.com/ClickHouse/ClickHouse/pull/53006) ([Maksim Kita](https://github.com/kitaisreal)).
- Make `hasTokenOrNull` and `hasTokenCaseInsensitiveOrNull` return null for empty needles. [#53059](https://github.com/ClickHouse/ClickHouse/pull/53059) ([ltrk2](https://github.com/ltrk2)).
- Allow to restrict allowed paths for filesystem caches. Mainly useful for dynamic disks. If in server config `filesystem_caches_path` is specified, all filesystem caches' paths will be restricted to this directory. E.g. if the `path` in cache config is relative - it will be put in `filesystem_caches_path`; if `path` in cache config is absolute, it will be required to lie inside `filesystem_caches_path`. If `filesystem_caches_path` is not specified in config, then behaviour will be the same as in earlier versions. [#53124](https://github.com/ClickHouse/ClickHouse/pull/53124) ([Kseniia Sumarokova](https://github.com/kssenii)).
- Added a bunch of custom commands (mostly to make ClickHouse debugging easier). [#53127](https://github.com/ClickHouse/ClickHouse/pull/53127) ([pufit](https://github.com/pufit)).
- Add diagnostic info about file name during schema inference - it helps when you process multiple files with globs. [#53135](https://github.com/ClickHouse/ClickHouse/pull/53135) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
- Client will load suggestions using the main connection if the second connection is not allowed to create a session. [#53177](https://github.com/ClickHouse/ClickHouse/pull/53177) ([Alexey Gerasimchuck](https://github.com/Demilivor)).
- Add EXCEPT clause to `SYSTEM STOP/START LISTEN QUERIES [ALL/DEFAULT/CUSTOM]` query, for example `SYSTEM STOP LISTEN QUERIES ALL EXCEPT TCP, HTTP`. [#53280](https://github.com/ClickHouse/ClickHouse/pull/53280) ([Nikolay Degterinsky](https://github.com/evillique)).
- Change the default of `max_concurrent_queries` from 100 to 1000. It's ok to have many concurrent queries if they are not heavy, and mostly waiting for the network. Note: don't confuse concurrent queries and QPS: for example, ClickHouse server can do tens of thousands of QPS with less than 100 concurrent queries. [#53285](https://github.com/ClickHouse/ClickHouse/pull/53285) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
- Limit number of concurrent background partition optimize merges. [#53405](https://github.com/ClickHouse/ClickHouse/pull/53405) ([Duc Canh Le](https://github.com/canhld94)).
- Added a setting `allow_moving_table_directory_to_trash` that allows to ignore `Directory for table data already exists` error when replicating/recovering a `Replicated` database. [#53425](https://github.com/ClickHouse/ClickHouse/pull/53425) ([Alexander Tokmakov](https://github.com/tavplubix)).
- If server settings `asynchronous_metrics_update_period_s` and `asynchronous_heavy_metrics_update_period_s` are misconfigured to 0, it will now fail gracefully instead of terminating the application. [#53428](https://github.com/ClickHouse/ClickHouse/pull/53428) ([Robert Schulze](https://github.com/rschu1ze)).
- 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)).