2019 Changelog

## ClickHouse Release 19.9[​](#clickhouse-release-19-9 "Direct link to ClickHouse Release 19.9")

### ClickHouse Release 19.9.3.31, 2019-07-05[​](#clickhouse-release-19-9-3-31-2019-07-05 "Direct link to ClickHouse Release 19.9.3.31, 2019-07-05")

#### Bug Fix[​](#bug-fix-23 "Direct link to Bug Fix")

- Fix segfault in Delta codec which affects columns with values less than 32 bits size. The bug led to random memory corruption. [#5786](https://github.com/ClickHouse/ClickHouse/pull/5786) ([alesapin](https://github.com/alesapin))
- Fix rare bug in checking of part with LowCardinality column. [#5832](https://github.com/ClickHouse/ClickHouse/pull/5832) ([alesapin](https://github.com/alesapin))
- Fix segfault in TTL merge with non-physical columns in block. [#5819](https://github.com/ClickHouse/ClickHouse/pull/5819) ([Anton Popov](https://github.com/CurtizJ))
- Fix potential infinite sleeping of low-priority queries. [#5842](https://github.com/ClickHouse/ClickHouse/pull/5842) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fix how ClickHouse determines default time zone as UCT instead of UTC. [#5828](https://github.com/ClickHouse/ClickHouse/pull/5828) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fix bug about executing distributed DROP/ALTER/TRUNCATE/OPTIMIZE ON CLUSTER queries on follower replica before leader replica. Now they will be executed directly on leader replica. [#5757](https://github.com/ClickHouse/ClickHouse/pull/5757) ([alesapin](https://github.com/alesapin))
- Fix race condition, which cause that some queries may not appear in query\_log instantly after SYSTEM FLUSH LOGS query. [#5685](https://github.com/ClickHouse/ClickHouse/pull/5685) ([Anton Popov](https://github.com/CurtizJ))
- Added missing support for constant arguments to `evalMLModel` function. [#5820](https://github.com/ClickHouse/ClickHouse/pull/5820) ([alexey-milovidov](https://github.com/alexey-milovidov))

### ClickHouse Release 19.9.2.4, 2019-06-24[​](#clickhouse-release-19-9-2-4-2019-06-24 "Direct link to ClickHouse Release 19.9.2.4, 2019-06-24")

#### New Feature[​](#new-feature-8 "Direct link to New Feature")

- Print information about frozen parts in `system.parts` table. [#5471](https://github.com/ClickHouse/ClickHouse/pull/5471) ([proller](https://github.com/proller))
- Ask client password on clickhouse-client start on tty if not set in arguments [#5092](https://github.com/ClickHouse/ClickHouse/pull/5092) ([proller](https://github.com/proller))
- Implement `dictGet` and `dictGetOrDefault` functions for Decimal types. [#5394](https://github.com/ClickHouse/ClickHouse/pull/5394) ([Artem Zuikov](https://github.com/4ertus2))

#### Improvement[​](#improvement-8 "Direct link to Improvement")

- Debian init: Add service stop timeout [#5522](https://github.com/ClickHouse/ClickHouse/pull/5522) ([proller](https://github.com/proller))
- Add setting forbidden by default to create table with suspicious types for LowCardinality [#5448](https://github.com/ClickHouse/ClickHouse/pull/5448) ([Olga Khvostikova](https://github.com/stavrolia))
- Regression functions return model weights when not used as State in function `evalMLMethod`. [#5411](https://github.com/ClickHouse/ClickHouse/pull/5411) ([Quid37](https://github.com/Quid37))
- Rename and improve regression methods. [#5492](https://github.com/ClickHouse/ClickHouse/pull/5492) ([Quid37](https://github.com/Quid37))
- Clearer interfaces of string searchers. [#5586](https://github.com/ClickHouse/ClickHouse/pull/5586) ([Danila Kutenin](https://github.com/danlark1))

#### Bug Fix[​](#bug-fix-24 "Direct link to Bug Fix")

- Fix potential data loss in Kafka [#5445](https://github.com/ClickHouse/ClickHouse/pull/5445) ([Ivan](https://github.com/abyss7))
- Fix potential infinite loop in `PrettySpace` format when called with zero columns [#5560](https://github.com/ClickHouse/ClickHouse/pull/5560) ([Olga Khvostikova](https://github.com/stavrolia))
- Fixed UInt32 overflow bug in linear models. Allow eval ML model for non-const model argument. [#5516](https://github.com/ClickHouse/ClickHouse/pull/5516) ([Nikolai Kochetov](https://github.com/KochetovNicolai))
- `ALTER TABLE ... DROP INDEX IF EXISTS ...` should not raise an exception if provided index does not exist [#5524](https://github.com/ClickHouse/ClickHouse/pull/5524) ([Gleb Novikov](https://github.com/NanoBjorn))
- Fix segfault with `bitmapHasAny` in scalar subquery [#5528](https://github.com/ClickHouse/ClickHouse/pull/5528) ([Zhichang Yu](https://github.com/yuzhichang))
- Fixed error when replication connection pool does not retry to resolve host, even when DNS cache was dropped. [#5534](https://github.com/ClickHouse/ClickHouse/pull/5534) ([alesapin](https://github.com/alesapin))
- Fixed `ALTER ... MODIFY TTL` on ReplicatedMergeTree. [#5539](https://github.com/ClickHouse/ClickHouse/pull/5539) ([Anton Popov](https://github.com/CurtizJ))
- Fix INSERT into Distributed table with MATERIALIZED column [#5429](https://github.com/ClickHouse/ClickHouse/pull/5429) ([Azat Khuzhin](https://github.com/azat))
- Fix bad alloc when truncate Join storage [#5437](https://github.com/ClickHouse/ClickHouse/pull/5437) ([TCeason](https://github.com/TCeason))
- In recent versions of package tzdata some of files are symlinks now. The current mechanism for detecting default timezone gets broken and gives wrong names for some timezones. Now at least we force the timezone name to the contents of TZ if provided. [#5443](https://github.com/ClickHouse/ClickHouse/pull/5443) ([Ivan](https://github.com/abyss7))
- Fix some extremely rare cases with MultiVolnitsky searcher when the constant needles in sum are at least 16KB long. The algorithm missed or overwrote the previous results which can lead to the incorrect result of `multiSearchAny`. [#5588](https://github.com/ClickHouse/ClickHouse/pull/5588) ([Danila Kutenin](https://github.com/danlark1))
- Fix the issue when settings for ExternalData requests couldn't use ClickHouse settings. Also, for now, settings `date_time_input_format` and `low_cardinality_allow_in_native_format` cannot be used because of the ambiguity of names (in external data it can be interpreted as table format and in the query it can be a setting). [#5455](https://github.com/ClickHouse/ClickHouse/pull/5455) ([Danila Kutenin](https://github.com/danlark1))
- Fix bug when parts were removed only from FS without dropping them from Zookeeper. [#5520](https://github.com/ClickHouse/ClickHouse/pull/5520) ([alesapin](https://github.com/alesapin))
- Remove debug logging from MySQL protocol [#5478](https://github.com/ClickHouse/ClickHouse/pull/5478) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Skip ZNONODE during DDL query processing [#5489](https://github.com/ClickHouse/ClickHouse/pull/5489) ([Azat Khuzhin](https://github.com/azat))
- Fix mix `UNION ALL` result column type. There were cases with inconsistent data and column types of resulting columns. [#5503](https://github.com/ClickHouse/ClickHouse/pull/5503) ([Artem Zuikov](https://github.com/4ertus2))
- Throw an exception on wrong integers in `dictGetT` functions instead of crash. [#5446](https://github.com/ClickHouse/ClickHouse/pull/5446) ([Artem Zuikov](https://github.com/4ertus2))
- Fix wrong element\_count and load\_factor for hashed dictionary in `system.dictionaries` table. [#5440](https://github.com/ClickHouse/ClickHouse/pull/5440) ([Azat Khuzhin](https://github.com/azat))

#### Build/Testing/Packaging Improvement[​](#buildtestingpackaging-improvement-9 "Direct link to Build/Testing/Packaging Improvement")