### ClickHouse release v20.5.2.7-stable FIXME as compared to v20.5.1.3833-prestable

#### New Feature
* Add `Alter table drop replica replica_name` support. This fixes [#7080](https://github.com/ClickHouse/ClickHouse/issues/7080). [#10679](https://github.com/ClickHouse/ClickHouse/pull/10679) ([sundyli](https://github.com/sundy-li)).

#### Improvement
* Add number of errors to ignore while choosing replicas (`distributed_replica_error_ignore`). [#11669](https://github.com/ClickHouse/ClickHouse/pull/11669) ([Azat Khuzhin](https://github.com/azat)).
* Multiversion metadata for storages without structure locks. [#11745](https://github.com/ClickHouse/ClickHouse/pull/11745) ([alesapin](https://github.com/alesapin)).
* Slightly relax the validation of ODBC connection string. If the hostname or username contains only word characters along with `.` and `-`, don't put it into curly braces. It is needed, because some ODBC drivers (e.g. PostgreSQL) don't understand when hostname is enclosed in curly braces. [#11845](https://github.com/ClickHouse/ClickHouse/pull/11845) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Support `SIGNED` and `UNSIGNED` modifiers of standard integer types (`BIGINT`, `INT`, ...) for compatibility with MySQL. [#11858](https://github.com/ClickHouse/ClickHouse/pull/11858) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Allow to use `sumWithOverflow` as `SimpleAggregateFunction`. Closes [#8053](https://github.com/ClickHouse/ClickHouse/issues/8053). [#11865](https://github.com/ClickHouse/ClickHouse/pull/11865) ([Alexander Kuzmenkov](https://github.com/akuzm)).
* Add FixedString support in Hashing functions. [#11878](https://github.com/ClickHouse/ClickHouse/pull/11878) ([flynn](https://github.com/ucasfl)).

#### Bug Fix
* Fix unexpected behaviour of queries like `SELECT *, xyz.*` which were success while an error expected. [#11753](https://github.com/ClickHouse/ClickHouse/pull/11753) ([hexiaoting](https://github.com/hexiaoting)).
* Fix wrong result for `if()` with NULLs in condition. [#11807](https://github.com/ClickHouse/ClickHouse/pull/11807) ([Artem Zuikov](https://github.com/4ertus2)).
* Fix memory accounting via HTTP interface (can be significant with `wait_end_of_query=1`). [#11840](https://github.com/ClickHouse/ClickHouse/pull/11840) ([Azat Khuzhin](https://github.com/azat)).
* Fix rare crash caused by using `Nullable` column in prewhere condition. Continuation of [#11608](https://github.com/ClickHouse/ClickHouse/issues/11608). [#11869](https://github.com/ClickHouse/ClickHouse/pull/11869) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
* Backported in [#11965](https://github.com/ClickHouse/ClickHouse/issues/11965): Fix potential floating point exception when parsing DateTime64. This fixes [#11374](https://github.com/ClickHouse/ClickHouse/issues/11374). [#11875](https://github.com/ClickHouse/ClickHouse/pull/11875) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Fix potential floating point exception when parsing DateTime64. This fixes [#11374](https://github.com/ClickHouse/ClickHouse/issues/11374). [#11875](https://github.com/ClickHouse/ClickHouse/pull/11875) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Backported in [#11963](https://github.com/ClickHouse/ClickHouse/issues/11963): Use the correct current database for checking access rights after statement `USE database`. [#11920](https://github.com/ClickHouse/ClickHouse/pull/11920) ([Vitaly Baranov](https://github.com/vitlibar)).
* Backported in [#12059](https://github.com/ClickHouse/ClickHouse/issues/12059): Fix incorrect comparison of tuples with `Nullable` columns. Fixes [#11985](https://github.com/ClickHouse/ClickHouse/issues/11985). [#12039](https://github.com/ClickHouse/ClickHouse/pull/12039) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).

#### Build/Testing/Packaging Improvement
* Add simple GitHub hook script for the serverless environment. [#11605](https://github.com/ClickHouse/ClickHouse/pull/11605) ([alesapin](https://github.com/alesapin)).
* Send logs to client on fatal errors if possible. This will make test results more readable. [#11826](https://github.com/ClickHouse/ClickHouse/pull/11826) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Allow ClickHouse to run on Android. [#11894](https://github.com/ClickHouse/ClickHouse/pull/11894) ([Alexey Milovidov](https://github.com/alexey-milovidov)).

#### NO CL ENTRY

* NO CL ENTRY:  'Merging [#10679](https://github.com/ClickHouse/ClickHouse/issues/10679)'. [#11896](https://github.com/ClickHouse/ClickHouse/pull/11896) ([Alexander Tokmakov](https://github.com/tavplubix)).
* NO CL ENTRY:  'Cherry pick [#11875](https://github.com/ClickHouse/ClickHouse/issues/11875) to 20.5: Fix strange and wrong code around DateTime64'. [#11958](https://github.com/ClickHouse/ClickHouse/pull/11958) ([Ivan](https://github.com/abyss7)).
