### ClickHouse release v20.11.2.1-stable FIXME as compared to v20.10.1.4881-prestable

#### Backward Incompatible Change
* Make rankCorr function return nan on insufficient data [#16124](https://github.com/ClickHouse/ClickHouse/issues/16124). [#16135](https://github.com/ClickHouse/ClickHouse/pull/16135) ([hexiaoting](https://github.com/hexiaoting)).
* Aggregate functions `boundingRatio`, `rankCorr`, `retention`, `timeSeriesGroupSum`, `timeSeriesGroupRateSum`, `windowFunnel` were erroneously made case-insensitive. Now their names are made case sensitive as designed. Only functions that are specified in SQL standard or made for compatibility with other DBMS or functions similar to those should be case-insensitive. [#16407](https://github.com/ClickHouse/ClickHouse/pull/16407) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Remove `ANALYZE` and `AST` queries, and make the setting `enable_debug_queries` obsolete since now it is the part of full featured `EXPLAIN` query. [#16536](https://github.com/ClickHouse/ClickHouse/pull/16536) ([Ivan](https://github.com/abyss7)).
* Restrict to use of non-comparable data types (like `AggregateFunction`) in keys (Sorting key, Primary key, Partition key, and so on). [#16601](https://github.com/ClickHouse/ClickHouse/pull/16601) ([alesapin](https://github.com/alesapin)).
* If some `profile` was specified in `distributed_ddl` config section, then this profile could overwrite settings of `default` profile on server startup. It's fixed, now settings of distributed DDL queries should not affect global server settings. [#16635](https://github.com/ClickHouse/ClickHouse/pull/16635) ([Alexander Tokmakov](https://github.com/tavplubix)).

#### New Feature
* #WelchTTest aggregate function implementation. [#10351](https://github.com/ClickHouse/ClickHouse/pull/10351) ([antikvist](https://github.com/antikvist)).
* New functions `encrypt`, `aes_encrypt_mysql`, `decrypt`, `aes_decrypt_mysql`. These functions are working slowly (below ClickHouse standards), so we consider it as an experimental feature. [#11844](https://github.com/ClickHouse/ClickHouse/pull/11844) ([Vasily Nemkov](https://github.com/Enmk)).
* - Added support of LDAP as a user directory for locally non-existent users. [#12736](https://github.com/ClickHouse/ClickHouse/pull/12736) ([Denis Glazachev](https://github.com/traceon)).
* Added `disable_merges` option for volumes in multi-disk configuration. [#13956](https://github.com/ClickHouse/ClickHouse/pull/13956) ([Vladimir Chebotarev](https://github.com/excitoon)).
* Added initial OpenTelemetry support. ClickHouse now accepts OpenTelemetry traceparent headers over Native and HTTP protocols, and passes them downstream in some cases. The trace spans for executed queries are saved into the `system.opentelemetry_span_log` table. [#14195](https://github.com/ClickHouse/ClickHouse/pull/14195) ([Alexander Kuzmenkov](https://github.com/akuzm)).
* Allows to read/write Single protobuf message at once (w/o length-delimiters). [#15199](https://github.com/ClickHouse/ClickHouse/pull/15199) ([filimonov](https://github.com/filimonov)).
* Add function `formatReadableTimeDelta` that format time delta to human readable string ... [#15497](https://github.com/ClickHouse/ClickHouse/pull/15497) ([Filipe Caixeta](https://github.com/filipecaixeta)).
* Add `tid` and `logTrace` function. This closes [#9434](https://github.com/ClickHouse/ClickHouse/issues/9434). [#15803](https://github.com/ClickHouse/ClickHouse/pull/15803) ([flynn](https://github.com/ucasfl)).
* Add a new option `print_query_id` to clickhouse-client. It helps generate arbitrary strings with the current query id generated by the client. [#15809](https://github.com/ClickHouse/ClickHouse/pull/15809) ([Amos Bird](https://github.com/amosbird)).
* Allow specify primary key in column list of CREATE TABLE query. [#15823](https://github.com/ClickHouse/ClickHouse/pull/15823) ([Maksim Kita](https://github.com/kitaisreal)).
* Added setting date_time_output_format. [#15845](https://github.com/ClickHouse/ClickHouse/pull/15845) ([Maksim Kita](https://github.com/kitaisreal)).
* Implement ``` OFFSET offset_row_count {ROW | ROWS} FETCH {FIRST | NEXT} fetch_row_count {ROW | ROWS} {ONLY | WITH TIES} ``` in select Query with order by. related issue:[#15367](https://github.com/ClickHouse/ClickHouse/issues/15367). [#15855](https://github.com/ClickHouse/ClickHouse/pull/15855) ([hexiaoting](https://github.com/hexiaoting)).
* Added an aggregate function, which calculates the p-value used for Welch's t-test. [#15874](https://github.com/ClickHouse/ClickHouse/pull/15874) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Add max_concurrent_queries_for_all_users setting, see [#6636](https://github.com/ClickHouse/ClickHouse/issues/6636) for use cases. [#16154](https://github.com/ClickHouse/ClickHouse/pull/16154) ([nvartolomei](https://github.com/nvartolomei)).
* Added minimal web UI to ClickHouse. [#16158](https://github.com/ClickHouse/ClickHouse/pull/16158) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Added function `untuple` which is a special function which can introduce new columns to the SELECT list by flattening a named tuple. [#16242](https://github.com/ClickHouse/ClickHouse/pull/16242) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Added toUUIDOrNull, toUUIDOrZero cast functions. [#16337](https://github.com/ClickHouse/ClickHouse/pull/16337) ([Maksim Kita](https://github.com/kitaisreal)).
* Add `system.replicated_fetches` table which shows currently running background fetches. [#16428](https://github.com/ClickHouse/ClickHouse/pull/16428) ([alesapin](https://github.com/alesapin)).
* - `errorCodeToName()` function - return variable name of the error (useful for analyzing query_log and similar) - `system.errors` table - shows how many times errors has been happened (respects `system_events_show_zero_values`). [#16438](https://github.com/ClickHouse/ClickHouse/pull/16438) ([Azat Khuzhin](https://github.com/azat)).
* Ability to create a docker image on the top of alpine. Uses precompiled binary and glibc components from ubuntu 20.04. [#16479](https://github.com/ClickHouse/ClickHouse/pull/16479) ([filimonov](https://github.com/filimonov)).
* Add `log_queries_min_query_duration_ms`, only queries slower then the value of this setting will go to `query_log`/`query_thread_log` (i.e. something like `slow_query_log` in mysql). [#16529](https://github.com/ClickHouse/ClickHouse/pull/16529) ([Azat Khuzhin](https://github.com/azat)).
* > Add farmFingerprint64 function. [#16570](https://github.com/ClickHouse/ClickHouse/pull/16570) ([Jacob Hayes](https://github.com/JacobHayes)).
* Now we can provide identifiers via query parameters. And these parameters can be used as table objects or columns. [#3815](https://github.com/ClickHouse/ClickHouse/issues/3815). [#16594](https://github.com/ClickHouse/ClickHouse/pull/16594) ([Amos Bird](https://github.com/amosbird)).
* Added big integers (UInt256, Int128, Int256) and UUID data types support for MergeTree BloomFilter index. [#16642](https://github.com/ClickHouse/ClickHouse/pull/16642) ([Maksim Kita](https://github.com/kitaisreal)).

#### Performance Improvement
* Speedup hashed/sparse_hashed dictionary loading by preallocating the hash table. [#15454](https://github.com/ClickHouse/ClickHouse/pull/15454) ([Azat Khuzhin](https://github.com/azat)).
* Do not merge parts across partitions in SELECT FINAL. [#15938](https://github.com/ClickHouse/ClickHouse/pull/15938) ([Kruglov Pavel](https://github.com/Avogar)).
* Improved performance of merges assignment in MergeTree table engines. Shouldn't be visible for the user. [#16191](https://github.com/ClickHouse/ClickHouse/pull/16191) ([alesapin](https://github.com/alesapin)).
* Improve performance of logical functions a little. [#16347](https://github.com/ClickHouse/ClickHouse/pull/16347) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Improve performance of `quantileMerge`. In previous versions it was obnoxiously slow. This closes [#1463](https://github.com/ClickHouse/ClickHouse/issues/1463). [#16643](https://github.com/ClickHouse/ClickHouse/pull/16643) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Improve performance of `-OrNull` and `-OrDefault` aggregate functions. [#16661](https://github.com/ClickHouse/ClickHouse/pull/16661) ([Alexey Milovidov](https://github.com/alexey-milovidov)).

#### Improvement
* Allow explicitly specify columns list in `CREATE TABLE table AS table_function(...)` query. Fixes [#9249](https://github.com/ClickHouse/ClickHouse/issues/9249) Fixes [#14214](https://github.com/ClickHouse/ClickHouse/issues/14214). [#14295](https://github.com/ClickHouse/ClickHouse/pull/14295) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Now trivial count optimization becomes slightly non-trivial. Predicates that contain exact partition expr can be optimized too. This also fixes [#11092](https://github.com/ClickHouse/ClickHouse/issues/11092) which returns wrong count when `max_parallel_replicas > 1`. [#15074](https://github.com/ClickHouse/ClickHouse/pull/15074) ([Amos Bird](https://github.com/amosbird)).
* Enable parsing enum values by their ids for CSV, TSV and JSON input formats. [#15685](https://github.com/ClickHouse/ClickHouse/pull/15685) ([vivarum](https://github.com/vivarum)).
* Add reconnects to `zookeeper-dump-tree` tool. [#15711](https://github.com/ClickHouse/ClickHouse/pull/15711) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Remove `MemoryTrackingInBackground*` metrics to avoid potentially misleading results. This fixes [#15684](https://github.com/ClickHouse/ClickHouse/issues/15684). [#15813](https://github.com/ClickHouse/ClickHouse/pull/15813) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Change level of some log messages from information to debug, so information messages will not appear for every query. This closes [#5293](https://github.com/ClickHouse/ClickHouse/issues/5293). [#15816](https://github.com/ClickHouse/ClickHouse/pull/15816) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix query hang (endless loop) in case of misconfiguration (`connections_with_failover_max_tries` set to 0). [#15876](https://github.com/ClickHouse/ClickHouse/pull/15876) ([Azat Khuzhin](https://github.com/azat)).
* Added boost::program_options to `db_generator` in order to increase its usability. This closes [#15940](https://github.com/ClickHouse/ClickHouse/issues/15940). [#15973](https://github.com/ClickHouse/ClickHouse/pull/15973) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Treat `INTERVAL '1 hour'` as equivalent to `INTERVAL 1 HOUR`, to be compatible with Postgres. This fixes [#15637](https://github.com/ClickHouse/ClickHouse/issues/15637). [#15978](https://github.com/ClickHouse/ClickHouse/pull/15978) ([flynn](https://github.com/ucasfl)).
* Add support of cache layout for Redis dictionaries with complex key. [#15985](https://github.com/ClickHouse/ClickHouse/pull/15985) ([Anton Popov](https://github.com/CurtizJ)).
* Fix rare issue when clickhouse-client may abort on exit due to loading of suggestions. This fixes [#16035](https://github.com/ClickHouse/ClickHouse/issues/16035). [#16047](https://github.com/ClickHouse/ClickHouse/pull/16047) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Now it's allowed to execute `ALTER ... ON CLUSTER` queries regardless of the `<internal_replication>` setting in cluster config. [#16075](https://github.com/ClickHouse/ClickHouse/pull/16075) ([alesapin](https://github.com/alesapin)).
* - Fix memory_profiler_step/max_untracked_memory for queries via HTTP (test included), and adjusting this value globally in xml config will not help either, since those settings are not applied anyway, only default (4MB) value is [used](https://github.com/ClickHouse/ClickHouse/blob/17731245336d8c84f75e4c0894c5797ed7732190/src/Common/ThreadStatus.h#L104). - Fix query_id for the most root ThreadStatus of the http query (by initializing QueryScope after reading query_id). [#16101](https://github.com/ClickHouse/ClickHouse/pull/16101) ([Azat Khuzhin](https://github.com/azat)).
* Add allow_nondeterministic_optimize_skip_unused_shards (to allow non deterministic like rand() or dictGet() in sharding key). [#16105](https://github.com/ClickHouse/ClickHouse/pull/16105) ([Azat Khuzhin](https://github.com/azat)).
* database_atomic_wait_for_drop_and_detach_synchronously/NO DELAY/SYNC for DROP DATABASE. [#16127](https://github.com/ClickHouse/ClickHouse/pull/16127) ([Azat Khuzhin](https://github.com/azat)).
* Add support for nested data types (like named tuple) as sub-types. Fixes [#15587](https://github.com/ClickHouse/ClickHouse/issues/15587). [#16262](https://github.com/ClickHouse/ClickHouse/pull/16262) ([Ivan](https://github.com/abyss7)).
* If there are no tmp folder in the system (chroot, misconfigutation etc) clickhouse-local will create temporary subfolder in the current directory. [#16280](https://github.com/ClickHouse/ClickHouse/pull/16280) ([filimonov](https://github.com/filimonov)).
* Now it's possible to specify `PRIMARY KEY` without `ORDER BY` for MergeTree table engines family. Closes [#15591](https://github.com/ClickHouse/ClickHouse/issues/15591). [#16284](https://github.com/ClickHouse/ClickHouse/pull/16284) ([alesapin](https://github.com/alesapin)).
* try use cmake version for croaring instead of amalgamation.sh. [#16285](https://github.com/ClickHouse/ClickHouse/pull/16285) ([sundyli](https://github.com/sundy-li)).
* Add total_rows/total_bytes (from system.tables) support for Set/Join table engines. [#16306](https://github.com/ClickHouse/ClickHouse/pull/16306) ([Azat Khuzhin](https://github.com/azat)).
* Better diagnostics when client has dropped connection. In previous versions, `Attempt to read after EOF` and `Broken pipe` exceptions were logged in server. In new version, it's information message `Client has dropped the connection, cancel the query.`. [#16329](https://github.com/ClickHouse/ClickHouse/pull/16329) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add `TablesToDropQueueSize` metric. It's equal to number of dropped tables, that are waiting for background data removal. [#16364](https://github.com/ClickHouse/ClickHouse/pull/16364) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Fix debug assertion in quantileDeterministic function. In previous version it may also transfer up to two times more data over the network. Although no bug existed. This fixes [#15683](https://github.com/ClickHouse/ClickHouse/issues/15683). [#16410](https://github.com/ClickHouse/ClickHouse/pull/16410) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Better read task scheduling for JBOD architecture and `MergeTree` storage. New setting `read_backoff_min_concurrency` which serves as the lower limit to the number of reading threads. [#16423](https://github.com/ClickHouse/ClickHouse/pull/16423) ([Amos Bird](https://github.com/amosbird)).
* Fixed bug for [#16263](https://github.com/ClickHouse/ClickHouse/issues/16263). Also minimized event loop lifetime. Added more efficient queues setup. [#16426](https://github.com/ClickHouse/ClickHouse/pull/16426) ([Kseniia Sumarokova](https://github.com/kssenii)).
* Allow to fetch parts that are already committed or outdated in the current instance into the detached directory. It's useful when migrating tables from another cluster and having N to 1 shards mapping. It's also consistent with the current fetchPartition implementation. [#16538](https://github.com/ClickHouse/ClickHouse/pull/16538) ([Amos Bird](https://github.com/amosbird)).
* Add current_database into query_thread_log. [#16558](https://github.com/ClickHouse/ClickHouse/pull/16558) ([Azat Khuzhin](https://github.com/azat)).
* Subqueries in WITH section (CTE) can reference previous subqueries in WITH section by their name. [#16575](https://github.com/ClickHouse/ClickHouse/pull/16575) ([Amos Bird](https://github.com/amosbird)).
* - Improve scheduling of background task which removes data of dropped tables in `Atomic` databases. - `Atomic` databases do not create broken symlink to table data directory if table actually has no data directory. [#16584](https://github.com/ClickHouse/ClickHouse/pull/16584) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Now paratmeterized functions can be used in APPLY column transformer. [#16589](https://github.com/ClickHouse/ClickHouse/pull/16589) ([Amos Bird](https://github.com/amosbird)).
* Now `event_time_microseconds` field stores in Decimal64, not UInt64. Removed an incorrect check from Field::get(). [#16617](https://github.com/ClickHouse/ClickHouse/pull/16617) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Apply SETTINGS clause as early as possible. It allows to modify more settings in the query. This closes [#3178](https://github.com/ClickHouse/ClickHouse/issues/3178). [#16619](https://github.com/ClickHouse/ClickHouse/pull/16619) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Better update of ZooKeeper configuration in runtime. [#16630](https://github.com/ClickHouse/ClickHouse/pull/16630) ([sundyli](https://github.com/sundy-li)).
* Make the behaviour of `minMap` and `maxMap` more desireable. It will not skip zero values in the result. Fixes [#16087](https://github.com/ClickHouse/ClickHouse/issues/16087). [#16631](https://github.com/ClickHouse/ClickHouse/pull/16631) ([Ildus Kurbangaliev](https://github.com/ildus)).
* Better diagnostics on parse errors in input data. Provide row number on `Cannot read all data` errors. [#16644](https://github.com/ClickHouse/ClickHouse/pull/16644) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Workaround for use S3 with nginx server as proxy. Nginx currenty does not accept urls with empty path like http://domain.com?delete, but vanilla aws-sdk-cpp produces this kind of urls. This commit uses patched aws-sdk-cpp version, which makes urls with "/" as path in this cases, like http://domain.com/?delete. [#16814](https://github.com/ClickHouse/ClickHouse/pull/16814) ([ianton-ru](https://github.com/ianton-ru)).

#### Bug Fix
* Update jemalloc to fix percpu_arena with affinity mask. [#15035](https://github.com/ClickHouse/ClickHouse/pull/15035) ([Azat Khuzhin](https://github.com/azat)).
* Decrement the `ReadonlyReplica` metric when detaching read-only tables. This fixes [#15598](https://github.com/ClickHouse/ClickHouse/issues/15598). [#15592](https://github.com/ClickHouse/ClickHouse/pull/15592) ([sundyli](https://github.com/sundy-li)).
* Fixed bug with globs in S3 table function, region from URL was not applied to S3 client configuration. [#15646](https://github.com/ClickHouse/ClickHouse/pull/15646) ([Vladimir Chebotarev](https://github.com/excitoon)).
* Fix error `Cannot add simple transform to empty Pipe` which happened while reading from `Buffer` table which has different structure than destination table. It was possible if destination table returned empty result for query. Fixes [#15529](https://github.com/ClickHouse/ClickHouse/issues/15529). [#15662](https://github.com/ClickHouse/ClickHouse/pull/15662) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Possibility to move part to another disk/volume if the first attempt was failed. [#15723](https://github.com/ClickHouse/ClickHouse/pull/15723) ([Pavel Kovalenko](https://github.com/Jokser)).
* Fix drop of materialized view with inner table in Atomic database (hangs all subsequent DROP TABLE due to hang of the worker thread, due to recursive DROP TABLE for inner table of MV). [#15743](https://github.com/ClickHouse/ClickHouse/pull/15743) ([Azat Khuzhin](https://github.com/azat)).
* Fix `select count()` inaccuracy for MaterializeMySQL. [#15767](https://github.com/ClickHouse/ClickHouse/pull/15767) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Fix exception `Block structure mismatch` in `SELECT ... ORDER BY DESC` queries which were executed after `ALTER MODIFY COLUMN` query. Fixes [#15800](https://github.com/ClickHouse/ClickHouse/issues/15800). [#15852](https://github.com/ClickHouse/ClickHouse/pull/15852) ([alesapin](https://github.com/alesapin)).
* Now exception will be thrown when `ALTER MODIFY COLUMN ... DEFAULT ...` has incompatible default with column type. Fixes [#15854](https://github.com/ClickHouse/ClickHouse/issues/15854). [#15858](https://github.com/ClickHouse/ClickHouse/pull/15858) ([alesapin](https://github.com/alesapin)).
* Fix possible deadlocks in RBAC. [#15875](https://github.com/ClickHouse/ClickHouse/pull/15875) ([Vitaly Baranov](https://github.com/vitlibar)).
* fixes [#12513](https://github.com/ClickHouse/ClickHouse/issues/12513) fix difference expressions with same alias when analyze queries again. [#15886](https://github.com/ClickHouse/ClickHouse/pull/15886) ([Winter Zhang](https://github.com/zhang2014)).
* Fix incorrect empty result for query from `Distributed` table if query has `WHERE`, `PREWHERE` and `GLOBAL IN`. Fixes [#15792](https://github.com/ClickHouse/ClickHouse/issues/15792). [#15933](https://github.com/ClickHouse/ClickHouse/pull/15933) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Fixed `DROP TABLE IF EXISTS` failure with `Table ... doesn't exist` error when table is concurrently renamed (for Atomic database engine). Fixed rare deadlock when concurrently executing some DDL queries with multiple tables (like `DROP DATABASE` and `RENAME TABLE`) Fixed `DROP/DETACH DATABASE` failure with `Table ... doesn't exist` when concurrently executing `DROP/DETACH TABLE`. [#15934](https://github.com/ClickHouse/ClickHouse/pull/15934) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Fix a crash when database creation fails. [#15954](https://github.com/ClickHouse/ClickHouse/pull/15954) ([Winter Zhang](https://github.com/zhang2014)).
* Fix ambiguity in parsing of settings profiles: `CREATE USER ... SETTINGS profile readonly` is now considered as using a profile named `readonly`, not a setting named `profile` with the readonly constraint. This fixes [#15628](https://github.com/ClickHouse/ClickHouse/issues/15628). [#15982](https://github.com/ClickHouse/ClickHouse/pull/15982) ([Vitaly Baranov](https://github.com/vitlibar)).
* Fix rare segfaults when inserting into or selecting from MaterializedView and concurrently dropping target table (for Atomic database engine). [#15984](https://github.com/ClickHouse/ClickHouse/pull/15984) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Prevent replica hang for 5-10 mins when replication error happens after a period of inactivity. [#15987](https://github.com/ClickHouse/ClickHouse/pull/15987) ([filimonov](https://github.com/filimonov)).
* Allow to use direct layout for dictionaries with complex keys. [#16007](https://github.com/ClickHouse/ClickHouse/pull/16007) ([Anton Popov](https://github.com/CurtizJ)).
* Fix collate name & charset name parser and support `length = 0` for string type. [#16008](https://github.com/ClickHouse/ClickHouse/pull/16008) ([Winter Zhang](https://github.com/zhang2014)).
* Fix `ALTER MODIFY ... ORDER BY` query hang for `ReplicatedVersionedCollapsingMergeTree`. This fixes [#15980](https://github.com/ClickHouse/ClickHouse/issues/15980). [#16011](https://github.com/ClickHouse/ClickHouse/pull/16011) ([alesapin](https://github.com/alesapin)).
* Fix bug with MySQL database. When MySQL server used as database engine is down some queries raise Exception, because they try to get tables from disabled server, while it's unnecessary. For example, query `SELECT ... FROM system.parts` should work only with MergeTree tables and don't touch MySQL database at all. [#16032](https://github.com/ClickHouse/ClickHouse/pull/16032) ([Kruglov Pavel](https://github.com/Avogar)).
* Fixes [#15780](https://github.com/ClickHouse/ClickHouse/issues/15780) regression, e.g. indexOf([1, 2, 3], toLowCardinality(1)) now is prohibited but it should not be. [#16038](https://github.com/ClickHouse/ClickHouse/pull/16038) ([Mike Kot](https://github.com/myrrc)).
* Fix segfault in some cases of wrong aggregation in lambdas. [#16082](https://github.com/ClickHouse/ClickHouse/pull/16082) ([Anton Popov](https://github.com/CurtizJ)).
* Fix the `clickhouse-local` crash when trying to do `OPTIMIZE` command. Fixes [#16076](https://github.com/ClickHouse/ClickHouse/issues/16076). [#16192](https://github.com/ClickHouse/ClickHouse/pull/16192) ([filimonov](https://github.com/filimonov)).
* Fix dictGet in sharding_key (and similar places, i.e. when the function context is stored permanently). [#16205](https://github.com/ClickHouse/ClickHouse/pull/16205) ([Azat Khuzhin](https://github.com/azat)).
* Fix the case when memory can be overallocated regardless to the limit. This closes [#14560](https://github.com/ClickHouse/ClickHouse/issues/14560). [#16206](https://github.com/ClickHouse/ClickHouse/pull/16206) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix a possible memory leak during `GROUP BY` with string keys, caused by an error in `TwoLevelStringHashTable` implementation. [#16264](https://github.com/ClickHouse/ClickHouse/pull/16264) ([Amos Bird](https://github.com/amosbird)).
* Fixed the inconsistent behaviour when a part of return data could be dropped because the set for its filtration wasn't created. [#16308](https://github.com/ClickHouse/ClickHouse/pull/16308) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Fix processing of very large entries in replication queue. Very large entries may appear in ALTER queries if table structure is extremely large (near 1 MB). This fixes [#16307](https://github.com/ClickHouse/ClickHouse/issues/16307). [#16332](https://github.com/ClickHouse/ClickHouse/pull/16332) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix async Distributed INSERT w/ prefer_localhost_replica=0 and internal_replication. [#16358](https://github.com/ClickHouse/ClickHouse/pull/16358) ([Azat Khuzhin](https://github.com/azat)).
* Fix group by with totals/rollup/cube modifers and min/max functions over group by keys. Fixes [#16393](https://github.com/ClickHouse/ClickHouse/issues/16393). [#16397](https://github.com/ClickHouse/ClickHouse/pull/16397) ([Anton Popov](https://github.com/CurtizJ)).
* Fix DROP TABLE for Distributed (racy with INSERT). [#16409](https://github.com/ClickHouse/ClickHouse/pull/16409) ([Azat Khuzhin](https://github.com/azat)).
* Fix double free in case of exception in function `dictGet`. It could have happened if dictionary was loaded with error. [#16429](https://github.com/ClickHouse/ClickHouse/pull/16429) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Specifically crafter argument of `round` function with `Decimal` was leading to integer division by zero. This fixes [#13338](https://github.com/ClickHouse/ClickHouse/issues/13338). [#16451](https://github.com/ClickHouse/ClickHouse/pull/16451) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix rapid growth of metadata when using MySQL Master -> MySQL Slave -> ClickHouse MaterializeMySQL Engine, and `slave_parallel_worker` enabled on MySQL Slave, by properly shrinking GTID sets. This fixes [#15951](https://github.com/ClickHouse/ClickHouse/issues/15951). [#16504](https://github.com/ClickHouse/ClickHouse/pull/16504) ([TCeason](https://github.com/TCeason)).
* Now when parsing AVRO from input the LowCardinality is removed from type. Fixes [#16188](https://github.com/ClickHouse/ClickHouse/issues/16188). [#16521](https://github.com/ClickHouse/ClickHouse/pull/16521) ([Mike Kot](https://github.com/myrrc)).
* Fix query_thread_log.query_duration_ms unit. [#16563](https://github.com/ClickHouse/ClickHouse/pull/16563) ([Azat Khuzhin](https://github.com/azat)).
* Calculation of `DEFAULT` expressions was involving possible name collisions (that was very unlikely to encounter). This fixes [#9359](https://github.com/ClickHouse/ClickHouse/issues/9359). [#16612](https://github.com/ClickHouse/ClickHouse/pull/16612) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Backported in [#16750](https://github.com/ClickHouse/ClickHouse/issues/16750): Fixed [#16081](https://github.com/ClickHouse/ClickHouse/issues/16081). [#16613](https://github.com/ClickHouse/ClickHouse/pull/16613) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Backported in [#16758](https://github.com/ClickHouse/ClickHouse/issues/16758): This will fix optimize_read_in_order/optimize_aggregation_in_order with max_threads>0 and expression in ORDER BY. [#16637](https://github.com/ClickHouse/ClickHouse/pull/16637) ([Azat Khuzhin](https://github.com/azat)).
* The setting `max_parallel_replicas` worked incorrectly if the queried table has no sampling. This fixes [#5733](https://github.com/ClickHouse/ClickHouse/issues/5733). [#16675](https://github.com/ClickHouse/ClickHouse/pull/16675) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Backported in [#16739](https://github.com/ClickHouse/ClickHouse/issues/16739): Fix `IN` operator over several columns and tuples with enabled `transform_null_in` setting. Fixes [#15310](https://github.com/ClickHouse/ClickHouse/issues/15310). [#16722](https://github.com/ClickHouse/ClickHouse/pull/16722) ([Anton Popov](https://github.com/CurtizJ)).
* Backported in [#16784](https://github.com/ClickHouse/ClickHouse/issues/16784): Mask password in data_path in the system.distribution_queue. [#16727](https://github.com/ClickHouse/ClickHouse/pull/16727) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#16785](https://github.com/ClickHouse/ClickHouse/issues/16785): Not for changelog. [#16757](https://github.com/ClickHouse/ClickHouse/pull/16757) ([Alexander Tokmakov](https://github.com/tavplubix)).

#### Build/Testing/Packaging Improvement
* Simplify Sys/V init script. [#14135](https://github.com/ClickHouse/ClickHouse/pull/14135) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix illegal code style `&vector[idx]` in libhdfs3. This fixes libcxx debug build. See also https://github.com/ClickHouse-Extras/libhdfs3/pull/8 . [#15815](https://github.com/ClickHouse/ClickHouse/pull/15815) ([Amos Bird](https://github.com/amosbird)).
* Check for `#pragma once` in headers. [#15818](https://github.com/ClickHouse/ClickHouse/pull/15818) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Check for executable bit on non-executable files. People often accidentially commit executable files from Windows. [#15843](https://github.com/ClickHouse/ClickHouse/pull/15843) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* - Updated RBAC syntax tests. - Updated `INSERT` and `SELECT` RBAC tests. - New RBAC tests for `ALTER` privileges by @ritaank - New RBAC tests for `MATERIALIZED`, `LIVE`, and standard `VIEWS`. - New RBAC tests for public system tables. - New RBAC tests for `SHOW TABLES`. [#16044](https://github.com/ClickHouse/ClickHouse/pull/16044) ([MyroTk](https://github.com/MyroTk)).
* Refuse to build with AppleClang because it's difficult to find out version correspondence. This closes [#16072](https://github.com/ClickHouse/ClickHouse/issues/16072). [#16074](https://github.com/ClickHouse/ClickHouse/pull/16074) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Add scipy to fasttest docker. [#16093](https://github.com/ClickHouse/ClickHouse/pull/16093) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* Add MySQL BinLog file check tool for MaterializeMySQL database engine. [#16223](https://github.com/ClickHouse/ClickHouse/pull/16223) ([Winter Zhang](https://github.com/zhang2014)).
* Add flaky check for stateless tests. [#16238](https://github.com/ClickHouse/ClickHouse/pull/16238) ([alesapin](https://github.com/alesapin)).
* Converting test tests/queries/0_stateless/01446_json_strings_each_row to a shell script. [#16247](https://github.com/ClickHouse/ClickHouse/pull/16247) ([vzakaznikov](https://github.com/vzakaznikov)).
* - None. [#16249](https://github.com/ClickHouse/ClickHouse/pull/16249) ([Denis Glazachev](https://github.com/traceon)).
* Fixing fails in LDAP external user directory tests. [#16363](https://github.com/ClickHouse/ClickHouse/pull/16363) ([vzakaznikov](https://github.com/vzakaznikov)).
* During config removal wrong exit code was expected. [#16365](https://github.com/ClickHouse/ClickHouse/pull/16365) ([vzakaznikov](https://github.com/vzakaznikov)).
* Fix LDAP tests by grabbing log size after container is stopped. [#16440](https://github.com/ClickHouse/ClickHouse/pull/16440) ([vzakaznikov](https://github.com/vzakaznikov)).
* Improve generation of build files for `ya.make` build system (Arcadia). [#16700](https://github.com/ClickHouse/ClickHouse/pull/16700) ([Alexey Milovidov](https://github.com/alexey-milovidov)).

#### Other
* Use only |name_parts| as primary name source and auto-generate full name. [#16149](https://github.com/ClickHouse/ClickHouse/pull/16149) ([Ivan](https://github.com/abyss7)).
* Rename struct NullSink from ReadHelpers to NullOutput, because class NullSink exists in Processors/NullSink.h. It's needed to prevent redefinition of 'NullSink' error. [#16520](https://github.com/ClickHouse/ClickHouse/pull/16520) ([Kruglov Pavel](https://github.com/Avogar)).

#### NO CL CATEGORY

* Try to make MergeTreeWriteAheadLog forward compatible. [#16094](https://github.com/ClickHouse/ClickHouse/pull/16094) ([nvartolomei](https://github.com/nvartolomei)).

#### NO CL ENTRY

* NO CL ENTRY:  'Revert "Write structure of table functions to metadata"'. [#15961](https://github.com/ClickHouse/ClickHouse/pull/15961) ([Alexander Tokmakov](https://github.com/tavplubix)).
* NO CL ENTRY:  'Revert "scipy"'. [#16156](https://github.com/ClickHouse/ClickHouse/pull/16156) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
* NO CL ENTRY:  'Bump markdown from 3.2.1 to 3.3.2 in /docs/tools'. [#16180](https://github.com/ClickHouse/ClickHouse/pull/16180) ([dependabot-preview[bot]](https://github.com/apps/dependabot-preview)).
* NO CL ENTRY:  'Revert "Optionally upload clickhouse binary in fast test"'. [#16333](https://github.com/ClickHouse/ClickHouse/pull/16333) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* NO CL ENTRY:  'minor fix.'. [#16335](https://github.com/ClickHouse/ClickHouse/pull/16335) ([Xianda Ke](https://github.com/kexianda)).
* NO CL ENTRY:  'Bump tornado from 5.1.1 to 6.1 in /docs/tools'. [#16590](https://github.com/ClickHouse/ClickHouse/pull/16590) ([dependabot-preview[bot]](https://github.com/apps/dependabot-preview)).
* NO CL ENTRY:  'Bump mkdocs-macros-plugin from 0.4.17 to 0.4.20 in /docs/tools'. [#16692](https://github.com/ClickHouse/ClickHouse/pull/16692) ([dependabot-preview[bot]](https://github.com/apps/dependabot-preview)).