2020 Changelog

- Removed logging from mutation finalization task if nothing was finalized. [#11109](https://github.com/ClickHouse/ClickHouse/pull/11109) ([alesapin](https://github.com/alesapin)).
- Fixed memory leak in registerDiskS3. [#11074](https://github.com/ClickHouse/ClickHouse/pull/11074) ([Pavel Kovalenko](https://github.com/Jokser)).
- Fixed the potential missed data during termination of Kafka engine table. [#11048](https://github.com/ClickHouse/ClickHouse/pull/11048) ([filimonov](https://github.com/filimonov)).
- Fixed `parseDateTime64BestEffort` argument resolution bugs. [#11038](https://github.com/ClickHouse/ClickHouse/pull/11038) ([Vasily Nemkov](https://github.com/Enmk)).
- Fixed very rare potential use-after-free error in `MergeTree` if table was not created successfully. [#10986](https://github.com/ClickHouse/ClickHouse/pull/10986), [#10970](https://github.com/ClickHouse/ClickHouse/pull/10970) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed metadata (relative path for rename) and data (relative path for symlink) handling for Atomic database. [#10980](https://github.com/ClickHouse/ClickHouse/pull/10980) ([Azat Khuzhin](https://github.com/azat)).
- Fixed server crash on concurrent `ALTER` and `DROP DATABASE` queries with `Atomic` database engine. [#10968](https://github.com/ClickHouse/ClickHouse/pull/10968) ([tavplubix](https://github.com/tavplubix)).
- Fixed incorrect raw data size in `getRawData()` method. [#10964](https://github.com/ClickHouse/ClickHouse/pull/10964) ([Igr](https://github.com/ObjatieGroba)).
- Fixed incompatibility of two-level aggregation between versions 20.1 and earlier. This incompatibility happens when different versions of ClickHouse are used on initiator node and remote nodes and the size of GROUP BY result is large and aggregation is performed by a single String field. It leads to several unmerged rows for a single key in result. [#10952](https://github.com/ClickHouse/ClickHouse/pull/10952) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed sending partially written files by the `DistributedBlockOutputStream`. [#10940](https://github.com/ClickHouse/ClickHouse/pull/10940) ([Azat Khuzhin](https://github.com/azat)).
- Fixed crash in `SELECT count(notNullIn(NULL, []))`. [#10920](https://github.com/ClickHouse/ClickHouse/pull/10920) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
- Fixed the hang which was happening sometimes during `DROP` of `Kafka` table engine. (or during server restarts). [#10910](https://github.com/ClickHouse/ClickHouse/pull/10910) ([filimonov](https://github.com/filimonov)).
- Fixed the impossibility of executing multiple `ALTER RENAME` like `a TO b, c TO a`. [#10895](https://github.com/ClickHouse/ClickHouse/pull/10895) ([alesapin](https://github.com/alesapin)).
- Fixed possible race which could happen when you get result from aggregate function state from multiple thread for the same column. The only way it can happen is when you use `finalizeAggregation` function while reading from table with `Memory` engine which stores `AggregateFunction` state for `quantile*` function. [#10890](https://github.com/ClickHouse/ClickHouse/pull/10890) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
- Fixed backward compatibility with tuples in Distributed tables. [#10889](https://github.com/ClickHouse/ClickHouse/pull/10889) ([Anton Popov](https://github.com/CurtizJ)).
- Fixed `SIGSEGV` in `StringHashTable` if such a key does not exist. [#10870](https://github.com/ClickHouse/ClickHouse/pull/10870) ([Azat Khuzhin](https://github.com/azat)).
- Fixed `WATCH` hangs after `LiveView` table was dropped from database with `Atomic` engine. [#10859](https://github.com/ClickHouse/ClickHouse/pull/10859) ([tavplubix](https://github.com/tavplubix)).
- Fixed bug in `ReplicatedMergeTree` which might cause some `ALTER` on `OPTIMIZE` query to hang waiting for some replica after it become inactive. [#10849](https://github.com/ClickHouse/ClickHouse/pull/10849) ([tavplubix](https://github.com/tavplubix)).
- Now constraints are updated if the column participating in `CONSTRAINT` expression was renamed. Fixes [#10844](https://github.com/ClickHouse/ClickHouse/issues/10844). [#10847](https://github.com/ClickHouse/ClickHouse/pull/10847) ([alesapin](https://github.com/alesapin)).
- Fixed potential read of uninitialized memory in cache-dictionary. [#10834](https://github.com/ClickHouse/ClickHouse/pull/10834) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed columns order after `Block::sortColumns()`. [#10826](https://github.com/ClickHouse/ClickHouse/pull/10826) ([Azat Khuzhin](https://github.com/azat)).
- Fixed the issue with `ODBC` bridge when no quoting of identifiers is requested. Fixes [#7984](https://github.com/ClickHouse/ClickHouse/issues/7984). [#10821](https://github.com/ClickHouse/ClickHouse/pull/10821) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed `UBSan` and `MSan` report in `DateLUT`. [#10798](https://github.com/ClickHouse/ClickHouse/pull/10798) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed incorrect type conversion in key conditions. Fixes [#6287](https://github.com/ClickHouse/ClickHouse/issues/6287). [#10791](https://github.com/ClickHouse/ClickHouse/pull/10791) ([Andrew Onyshchuk](https://github.com/oandrew)).
- Fixed `parallel_view_processing` behavior. Now all insertions into `MATERIALIZED VIEW` without exception should be finished if exception happened. Fixes [#10241](https://github.com/ClickHouse/ClickHouse/issues/10241). [#10757](https://github.com/ClickHouse/ClickHouse/pull/10757) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
- Fixed combinator `-OrNull` and `-OrDefault` when combined with `-State`. [#10741](https://github.com/ClickHouse/ClickHouse/pull/10741) ([hcz](https://github.com/hczhcz)).
- Fixed possible buffer overflow in function `h3EdgeAngle`. [#10711](https://github.com/ClickHouse/ClickHouse/pull/10711) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed bug which locks concurrent alters when table has a lot of parts. [#10659](https://github.com/ClickHouse/ClickHouse/pull/10659) ([alesapin](https://github.com/alesapin)).
- Fixed `nullptr` dereference in `StorageBuffer` if server was shutdown before table startup. [#10641](https://github.com/ClickHouse/ClickHouse/pull/10641) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed `optimize_skip_unused_shards` with `LowCardinality`. [#10611](https://github.com/ClickHouse/ClickHouse/pull/10611) ([Azat Khuzhin](https://github.com/azat)).
- Fixed handling condition variable for synchronous mutations. In some cases signals to that condition variable could be lost. [#10588](https://github.com/ClickHouse/ClickHouse/pull/10588) ([Vladimir Chebotarev](https://github.com/excitoon)).
- Fixed possible crash when `createDictionary()` is called before `loadStoredObject()` has finished. [#10587](https://github.com/ClickHouse/ClickHouse/pull/10587) ([Vitaly Baranov](https://github.com/vitlibar)).
- Fixed `SELECT` of column `ALIAS` which default expression type different from column type. [#10563](https://github.com/ClickHouse/ClickHouse/pull/10563) ([Azat Khuzhin](https://github.com/azat)).
- Implemented comparison between DateTime64 and String values. [#10560](https://github.com/ClickHouse/ClickHouse/pull/10560) ([Vasily Nemkov](https://github.com/Enmk)).
- Disable `GROUP BY` sharding\_key optimization by default (`optimize_distributed_group_by_sharding_key` had been introduced and turned of by default, due to trickery of sharding\_key analyzing, simple example is `if` in sharding key) and fix it for `WITH ROLLUP/CUBE/TOTALS`. [#10516](https://github.com/ClickHouse/ClickHouse/pull/10516) ([Azat Khuzhin](https://github.com/azat)).
- Fixed [#10263](https://github.com/ClickHouse/ClickHouse/issues/10263). [#10486](https://github.com/ClickHouse/ClickHouse/pull/10486) ([Azat Khuzhin](https://github.com/azat)).
- Added tests about `max_rows_to_sort` setting. [#10268](https://github.com/ClickHouse/ClickHouse/pull/10268) ([alexey-milovidov](https://github.com/alexey-milovidov)).