2019 Changelog

[Edit this page](https://github.com/ClickHouse/clickhouse-docs/blob/main/docs/whats-new/changelog/2019.md)

## ClickHouse Release 19.17[​](#clickhouse-release-v19-17 "Direct link to ClickHouse Release 19.17")

### ClickHouse Release 19.17.6.36, 2019-12-27[​](#clickhouse-release-v19-17-6-36-2019-12-27 "Direct link to ClickHouse Release 19.17.6.36, 2019-12-27")

#### Bug Fix[​](#bug-fix "Direct link to Bug Fix")

- Fixed potential buffer overflow in decompress. Malicious user can pass fabricated compressed data that could cause read after buffer. This issue was found by Eldar Zaitov from Yandex information security team. [#8404](https://github.com/ClickHouse/ClickHouse/pull/8404) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fixed possible server crash (`std::terminate`) when the server cannot send or write data in JSON or XML format with values of String data type (that require UTF-8 validation) or when compressing result data with Brotli algorithm or in some other rare cases. [#8384](https://github.com/ClickHouse/ClickHouse/pull/8384) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fixed dictionaries with source from a clickhouse `VIEW`, now reading such dictionaries does not cause the error `There is no query`. [#8351](https://github.com/ClickHouse/ClickHouse/pull/8351) ([Nikolai Kochetov](https://github.com/KochetovNicolai))
- Fixed checking if a client host is allowed by host\_regexp specified in users.xml. [#8241](https://github.com/ClickHouse/ClickHouse/pull/8241), [#8342](https://github.com/ClickHouse/ClickHouse/pull/8342) ([Vitaly Baranov](https://github.com/vitlibar))
- `RENAME TABLE` for a distributed table now renames the folder containing inserted data before sending to shards. This fixes an issue with successive renames `tableA->tableB`, `tableC->tableA`. [#8306](https://github.com/ClickHouse/ClickHouse/pull/8306) ([tavplubix](https://github.com/tavplubix))
- `range_hashed` external dictionaries created by DDL queries now allow ranges of arbitrary numeric types. [#8275](https://github.com/ClickHouse/ClickHouse/pull/8275) ([alesapin](https://github.com/alesapin))
- Fixed `INSERT INTO table SELECT ... FROM mysql(...)` table function. [#8234](https://github.com/ClickHouse/ClickHouse/pull/8234) ([tavplubix](https://github.com/tavplubix))
- Fixed segfault in `INSERT INTO TABLE FUNCTION file()` while inserting into a file which does not exist. Now in this case file would be created and then insert would be processed. [#8177](https://github.com/ClickHouse/ClickHouse/pull/8177) ([Olga Khvostikova](https://github.com/stavrolia))
- Fixed bitmapAnd error when intersecting an aggregated bitmap and a scalar bitmap. [#8082](https://github.com/ClickHouse/ClickHouse/pull/8082) ([Yue Huang](https://github.com/moon03432))
- Fixed segfault when `EXISTS` query was used without `TABLE` or `DICTIONARY` qualifier, just like `EXISTS t`. [#8213](https://github.com/ClickHouse/ClickHouse/pull/8213) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fixed return type for functions `rand` and `randConstant` in case of nullable argument. Now functions always return `UInt32` and never `Nullable(UInt32)`. [#8204](https://github.com/ClickHouse/ClickHouse/pull/8204) ([Nikolai Kochetov](https://github.com/KochetovNicolai))
- Fixed `DROP DICTIONARY IF EXISTS db.dict`, now it does not throw exception if `db` does not exist. [#8185](https://github.com/ClickHouse/ClickHouse/pull/8185) ([Vitaly Baranov](https://github.com/vitlibar))
- If a table wasn't completely dropped because of server crash, the server will try to restore and load it [#8176](https://github.com/ClickHouse/ClickHouse/pull/8176) ([tavplubix](https://github.com/tavplubix))
- Fixed a trivial count query for a distributed table if there are more than two shard local table. [#8164](https://github.com/ClickHouse/ClickHouse/pull/8164) ([小路](https://github.com/nicelulu))
- Fixed bug that lead to a data race in DB::BlockStreamProfileInfo::calculateRowsBeforeLimit() [#8143](https://github.com/ClickHouse/ClickHouse/pull/8143) ([Alexander Kazakov](https://github.com/Akazz))
- Fixed `ALTER table MOVE part` executed immediately after merging the specified part, which could cause moving a part which the specified part merged into. Now it correctly moves the specified part. [#8104](https://github.com/ClickHouse/ClickHouse/pull/8104) ([Vladimir Chebotarev](https://github.com/excitoon))
- Expressions for dictionaries can be specified as strings now. This is useful for calculation of attributes while extracting data from non-ClickHouse sources because it allows to use non-ClickHouse syntax for those expressions. [#8098](https://github.com/ClickHouse/ClickHouse/pull/8098) ([alesapin](https://github.com/alesapin))
- Fixed a very rare race in `clickhouse-copier` because of an overflow in ZXid. [#8088](https://github.com/ClickHouse/ClickHouse/pull/8088) ([Ding Xiang Fei](https://github.com/dingxiangfei2009))
- Fixed the bug when after the query failed (due to "Too many simultaneous queries" for example) it would not read external tables info, and the
  next request would interpret this info as the beginning of the next query causing an error like `Unknown packet from client`. [#8084](https://github.com/ClickHouse/ClickHouse/pull/8084) ([Azat Khuzhin](https://github.com/azat))
- Avoid null dereference after "Unknown packet X from server" [#8071](https://github.com/ClickHouse/ClickHouse/pull/8071) ([Azat Khuzhin](https://github.com/azat))
- Restore support of all ICU locales, add the ability to apply collations for constant expressions and add language name to system.collations table. [#8051](https://github.com/ClickHouse/ClickHouse/pull/8051) ([alesapin](https://github.com/alesapin))
- Number of streams for read from `StorageFile` and `StorageHDFS` is now limited, to avoid exceeding the memory limit. [#7981](https://github.com/ClickHouse/ClickHouse/pull/7981) ([alesapin](https://github.com/alesapin))
- Fixed `CHECK TABLE` query for `*MergeTree` tables without key. [#7979](https://github.com/ClickHouse/ClickHouse/pull/7979) ([alesapin](https://github.com/alesapin))
- Removed the mutation number from a part name in case there were no mutations. This removing improved the compatibility with older versions. [#8250](https://github.com/ClickHouse/ClickHouse/pull/8250) ([alesapin](https://github.com/alesapin))
- Fixed the bug that mutations are skipped for some attached parts due to their data\_version are larger than the table mutation version. [#7812](https://github.com/ClickHouse/ClickHouse/pull/7812) ([Zhichang Yu](https://github.com/yuzhichang))
- Allow starting the server with redundant copies of parts after moving them to another device. [#7810](https://github.com/ClickHouse/ClickHouse/pull/7810) ([Vladimir Chebotarev](https://github.com/excitoon))
- Fixed the error "Sizes of columns does not match" that might appear when using aggregate function columns. [#7790](https://github.com/ClickHouse/ClickHouse/pull/7790) ([Boris Granveaud](https://github.com/bgranvea))
- Now an exception will be thrown in case of using WITH TIES alongside LIMIT BY. And now it's possible to use TOP with LIMIT BY. [#7637](https://github.com/ClickHouse/ClickHouse/pull/7637) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov))
- Fix dictionary reload if it has `invalidate_query`, which stopped updates and some exception on previous update tries. [#8029](https://github.com/ClickHouse/ClickHouse/pull/8029) ([alesapin](https://github.com/alesapin))

### ClickHouse Release 19.17.4.11, 2019-11-22[​](#clickhouse-release-v19-17-4-11-2019-11-22 "Direct link to ClickHouse Release 19.17.4.11, 2019-11-22")

#### Backward Incompatible Change[​](#backward-incompatible-change "Direct link to Backward Incompatible Change")