2020 Changelog

- Fixed `dictGet` arguments check during GROUP BY injective functions elimination. [#12179](https://github.com/ClickHouse/ClickHouse/pull/12179) ([Azat Khuzhin](https://github.com/azat)).
- Don't split the dictionary source's table name into schema and table name itself if ODBC connection does not support schema. [#12165](https://github.com/ClickHouse/ClickHouse/pull/12165) ([Vitaly Baranov](https://github.com/vitlibar)).
- Fixed wrong logic in `ALTER DELETE` that leads to deleting of records when condition evaluates to NULL. This fixes [#9088](https://github.com/ClickHouse/ClickHouse/issues/9088). This closes [#12106](https://github.com/ClickHouse/ClickHouse/issues/12106). [#12153](https://github.com/ClickHouse/ClickHouse/pull/12153) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed transform of query to send to external DBMS (e.g. MySQL, ODBC) in presense of aliases. This fixes [#12032](https://github.com/ClickHouse/ClickHouse/issues/12032). [#12151](https://github.com/ClickHouse/ClickHouse/pull/12151) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed potential overflow in integer division. This fixes [#12119](https://github.com/ClickHouse/ClickHouse/issues/12119). [#12140](https://github.com/ClickHouse/ClickHouse/pull/12140) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed potential infinite loop in `greatCircleDistance`, `geoDistance`. This fixes [#12117](https://github.com/ClickHouse/ClickHouse/issues/12117). [#12137](https://github.com/ClickHouse/ClickHouse/pull/12137) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Normalize "pid" file handling. In previous versions the server may refuse to start if it was killed without proper shutdown and if there is another process that has the same pid as previously runned server. Also pid file may be removed in unsuccessful server startup even if there is another server running. This fixes [#3501](https://github.com/ClickHouse/ClickHouse/issues/3501). [#12133](https://github.com/ClickHouse/ClickHouse/pull/12133) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed handling dependency of table with ENGINE=Dictionary on dictionary. This fixes [#10994](https://github.com/ClickHouse/ClickHouse/issues/10994). This fixes [#10397](https://github.com/ClickHouse/ClickHouse/issues/10397). [#12116](https://github.com/ClickHouse/ClickHouse/pull/12116) ([Vitaly Baranov](https://github.com/vitlibar)).
- Fixed performance for selects with `UNION` caused by wrong limit for the total number of threads. Fixes [#12030](https://github.com/ClickHouse/ClickHouse/issues/12030). [#12103](https://github.com/ClickHouse/ClickHouse/pull/12103) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
- Fixed segfault with `-StateResample` combinators. [#12092](https://github.com/ClickHouse/ClickHouse/pull/12092) ([Anton Popov](https://github.com/CurtizJ)).
- Fixed empty `result_rows` and `result_bytes` metrics in `system.quey_log` for selects. Fixes [#11595](https://github.com/ClickHouse/ClickHouse/issues/11595). [#12089](https://github.com/ClickHouse/ClickHouse/pull/12089) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
- Fixed unnecessary limiting the number of threads for selects from `VIEW`. Fixes [#11937](https://github.com/ClickHouse/ClickHouse/issues/11937). [#12085](https://github.com/ClickHouse/ClickHouse/pull/12085) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
- Fixed possible crash while using wrong type for `PREWHERE`. Fixes [#12053](https://github.com/ClickHouse/ClickHouse/issues/12053), [#12060](https://github.com/ClickHouse/ClickHouse/issues/12060). [#12060](https://github.com/ClickHouse/ClickHouse/pull/12060) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
- Fixed error `Expected single dictionary argument for function` for function `defaultValueOfArgumentType` with `LowCardinality` type. Fixes [#11808](https://github.com/ClickHouse/ClickHouse/issues/11808). [#12056](https://github.com/ClickHouse/ClickHouse/pull/12056) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
- Fixed error `Cannot capture column` for higher-order functions with `Tuple(LowCardinality)` argument. Fixes [#9766](https://github.com/ClickHouse/ClickHouse/issues/9766). [#12055](https://github.com/ClickHouse/ClickHouse/pull/12055) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
- Parse tables metadata in parallel when loading database. This fixes slow server startup when there are large number of tables. [#12045](https://github.com/ClickHouse/ClickHouse/pull/12045) ([tavplubix](https://github.com/tavplubix)).
- Make `topK` aggregate function return Enum for Enum types. This fixes [#3740](https://github.com/ClickHouse/ClickHouse/issues/3740). [#12043](https://github.com/ClickHouse/ClickHouse/pull/12043) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed constraints check if constraint is a constant expression. This fixes [#11360](https://github.com/ClickHouse/ClickHouse/issues/11360). [#12042](https://github.com/ClickHouse/ClickHouse/pull/12042) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed 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)).
- Fixed calculation of access rights when allow\_introspection\_functions=0. [#12031](https://github.com/ClickHouse/ClickHouse/pull/12031) ([Vitaly Baranov](https://github.com/vitlibar)).
- Fixed wrong result and potential crash when invoking function `if` with arguments of type `FixedString` with different sizes. This fixes [#11362](https://github.com/ClickHouse/ClickHouse/issues/11362). [#12021](https://github.com/ClickHouse/ClickHouse/pull/12021) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- A query with function `neighbor` as the only returned expression may return empty result if the function is called with offset `-9223372036854775808`. This fixes [#11367](https://github.com/ClickHouse/ClickHouse/issues/11367). [#12019](https://github.com/ClickHouse/ClickHouse/pull/12019) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed calculation of access rights when allow\_ddl=0. [#12015](https://github.com/ClickHouse/ClickHouse/pull/12015) ([Vitaly Baranov](https://github.com/vitlibar)).
- Fixed potential array size overflow in generateRandom that may lead to crash. This fixes [#11371](https://github.com/ClickHouse/ClickHouse/issues/11371). [#12013](https://github.com/ClickHouse/ClickHouse/pull/12013) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed potential floating point exception. This closes [#11378](https://github.com/ClickHouse/ClickHouse/issues/11378). [#12005](https://github.com/ClickHouse/ClickHouse/pull/12005) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed wrong setting name in log message at server startup. [#11997](https://github.com/ClickHouse/ClickHouse/pull/11997) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed `Query parameter was not set` in `Values` format. Fixes [#11918](https://github.com/ClickHouse/ClickHouse/issues/11918). [#11936](https://github.com/ClickHouse/ClickHouse/pull/11936) ([tavplubix](https://github.com/tavplubix)).
- Keep aliases for substitutions in query (parametrized queries). This fixes [#11914](https://github.com/ClickHouse/ClickHouse/issues/11914). [#11916](https://github.com/ClickHouse/ClickHouse/pull/11916) ([alexey-milovidov](https://github.com/alexey-milovidov)).
- Fixed bug with no moves when changing storage policy from default one. [#11893](https://github.com/ClickHouse/ClickHouse/pull/11893) ([Vladimir Chebotarev](https://github.com/excitoon)).
- Fixed 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)).