2019 Changelog

### ClickHouse Release 19.11.11.57, 2019-09-13[​](#clickhouse-release-19-11-11-57-2019-09-13 "Direct link to ClickHouse Release 19.11.11.57, 2019-09-13")

- Fix logical error causing segfaults when selecting from Kafka empty topic. [#6902](https://github.com/ClickHouse/ClickHouse/issues/6902) [#6909](https://github.com/ClickHouse/ClickHouse/pull/6909) ([Ivan](https://github.com/abyss7))
- Fix for function `АrrayEnumerateUniqRanked` with empty arrays in params. [#6928](https://github.com/ClickHouse/ClickHouse/pull/6928) ([proller](https://github.com/proller))

### ClickHouse Release 19.11.10.54, 2019-09-10[​](#clickhouse-release-19-11-10-54-2019-09-10 "Direct link to ClickHouse Release 19.11.10.54, 2019-09-10")

#### Bug Fix[​](#bug-fix-16 "Direct link to Bug Fix")

- Do store offsets for Kafka messages manually to be able to commit them all at once for all partitions. Fixes potential duplication in "one consumer - many partitions" scenario. [#6872](https://github.com/ClickHouse/ClickHouse/pull/6872) ([Ivan](https://github.com/abyss7))

### ClickHouse Release 19.11.9.52, 2019-09-6[​](#clickhouse-release-19-11-9-52-2019-09-6 "Direct link to ClickHouse Release 19.11.9.52, 2019-09-6")

- Improve error handling in cache dictionaries. [#6737](https://github.com/ClickHouse/ClickHouse/pull/6737) ([Vitaly Baranov](https://github.com/vitlibar))
- Fixed bug in function `arrayEnumerateUniqRanked`. [#6779](https://github.com/ClickHouse/ClickHouse/pull/6779) ([proller](https://github.com/proller))
- Fix `JSONExtract` function while extracting a `Tuple` from JSON. [#6718](https://github.com/ClickHouse/ClickHouse/pull/6718) ([Vitaly Baranov](https://github.com/vitlibar))
- Fixed possible data loss after `ALTER DELETE` query on table with skipping index. [#6224](https://github.com/ClickHouse/ClickHouse/issues/6224) [#6282](https://github.com/ClickHouse/ClickHouse/pull/6282) ([Nikita Vasilev](https://github.com/nikvas0))
- Fixed performance test. [#6392](https://github.com/ClickHouse/ClickHouse/pull/6392) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Parquet: Fix reading boolean columns. [#6579](https://github.com/ClickHouse/ClickHouse/pull/6579) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fixed wrong behaviour of `nullIf` function for constant arguments. [#6518](https://github.com/ClickHouse/ClickHouse/pull/6518) ([Guillaume Tassery](https://github.com/YiuRULE)) [#6580](https://github.com/ClickHouse/ClickHouse/pull/6580) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fix Kafka messages duplication problem on normal server restart. [#6597](https://github.com/ClickHouse/ClickHouse/pull/6597) ([Ivan](https://github.com/abyss7))
- Fixed an issue when long `ALTER UPDATE` or `ALTER DELETE` may prevent regular merges to run. Prevent mutations from executing if there is no enough free threads available. [#6502](https://github.com/ClickHouse/ClickHouse/issues/6502) [#6617](https://github.com/ClickHouse/ClickHouse/pull/6617) ([tavplubix](https://github.com/tavplubix))
- Fixed error with processing "timezone" in server configuration file. [#6709](https://github.com/ClickHouse/ClickHouse/pull/6709) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fix kafka tests. [#6805](https://github.com/ClickHouse/ClickHouse/pull/6805) ([Ivan](https://github.com/abyss7))

#### Security Fix[​](#security-fix-3 "Direct link to Security Fix")

- If the attacker has write access to ZooKeeper and is able to run custom server available from the network where ClickHouse runs, it can create custom-built malicious server that will act as ClickHouse replica and register it in ZooKeeper. When another replica will fetch data part from malicious replica, it can force clickhouse-server to write to arbitrary path on filesystem. Found by Eldar Zaitov, information security team at Yandex. [#6247](https://github.com/ClickHouse/ClickHouse/pull/6247) ([alexey-milovidov](https://github.com/alexey-milovidov))

### ClickHouse Release 19.11.8.46, 2019-08-22[​](#clickhouse-release-19-11-8-46-2019-08-22 "Direct link to ClickHouse Release 19.11.8.46, 2019-08-22")

#### Bug Fix[​](#bug-fix-17 "Direct link to Bug Fix")

- Fix `ALTER TABLE ... UPDATE` query for tables with `enable_mixed_granularity_parts=1`. [#6543](https://github.com/ClickHouse/ClickHouse/pull/6543) ([alesapin](https://github.com/alesapin))
- Fix NPE when using IN clause with a subquery with a tuple. [#6125](https://github.com/ClickHouse/ClickHouse/issues/6125) [#6550](https://github.com/ClickHouse/ClickHouse/pull/6550) ([tavplubix](https://github.com/tavplubix))
- Fixed an issue that if a stale replica becomes alive, it may still have data parts that were removed by DROP PARTITION. [#6522](https://github.com/ClickHouse/ClickHouse/issues/6522) [#6523](https://github.com/ClickHouse/ClickHouse/pull/6523) ([tavplubix](https://github.com/tavplubix))
- Fixed issue with parsing CSV [#6426](https://github.com/ClickHouse/ClickHouse/issues/6426) [#6559](https://github.com/ClickHouse/ClickHouse/pull/6559) ([tavplubix](https://github.com/tavplubix))
- Fixed data race in system.parts table and ALTER query. This fixes [#6245](https://github.com/ClickHouse/ClickHouse/issues/6245). [#6513](https://github.com/ClickHouse/ClickHouse/pull/6513) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fixed wrong code in mutations that may lead to memory corruption. Fixed segfault with read of address `0x14c0` that may happed due to concurrent `DROP TABLE` and `SELECT` from `system.parts` or `system.parts_columns`. Fixed race condition in preparation of mutation queries. Fixed deadlock caused by `OPTIMIZE` of Replicated tables and concurrent modification operations like ALTERs. [#6514](https://github.com/ClickHouse/ClickHouse/pull/6514) ([alexey-milovidov](https://github.com/alexey-milovidov))

### ClickHouse Release 19.11.7.40, 2019-08-14[​](#clickhouse-release-19-11-7-40-2019-08-14 "Direct link to ClickHouse Release 19.11.7.40, 2019-08-14")

#### Bug Fix[​](#bug-fix-18 "Direct link to Bug Fix")