2019 Changelog

### 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")

- Kafka integration has been fixed in this version.
- Fix segfault when using `arrayReduce` for constant arguments. [#6326](https://github.com/ClickHouse/ClickHouse/pull/6326) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fixed `toFloat()` monotonicity. [#6374](https://github.com/ClickHouse/ClickHouse/pull/6374) ([dimarub2000](https://github.com/dimarub2000))
- Fix segfault with enabled `optimize_skip_unused_shards` and missing sharding key. [#6384](https://github.com/ClickHouse/ClickHouse/pull/6384) ([CurtizJ](https://github.com/CurtizJ))
- Fixed logic of `arrayEnumerateUniqRanked` function. [#6423](https://github.com/ClickHouse/ClickHouse/pull/6423) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Removed extra verbose logging from MySQL handler. [#6389](https://github.com/ClickHouse/ClickHouse/pull/6389) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fix wrong behavior and possible segfaults in `topK` and `topKWeighted` aggregated functions. [#6404](https://github.com/ClickHouse/ClickHouse/pull/6404) ([CurtizJ](https://github.com/CurtizJ))
- Do not expose virtual columns in `system.columns` table. This is required for backward compatibility. [#6406](https://github.com/ClickHouse/ClickHouse/pull/6406) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fix bug with memory allocation for string fields in complex key cache dictionary. [#6447](https://github.com/ClickHouse/ClickHouse/pull/6447) ([alesapin](https://github.com/alesapin))
- Fix bug with enabling adaptive granularity when creating new replica for `Replicated*MergeTree` table. [#6452](https://github.com/ClickHouse/ClickHouse/pull/6452) ([alesapin](https://github.com/alesapin))
- Fix infinite loop when reading Kafka messages. [#6354](https://github.com/ClickHouse/ClickHouse/pull/6354) ([abyss7](https://github.com/abyss7))
- Fixed the possibility of a fabricated query to cause server crash due to stack overflow in SQL parser and possibility of stack overflow in `Merge` and `Distributed` tables [#6433](https://github.com/ClickHouse/ClickHouse/pull/6433) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fixed Gorilla encoding error on small sequences. [#6444](https://github.com/ClickHouse/ClickHouse/pull/6444) ([Enmk](https://github.com/Enmk))

#### Improvement[​](#improvement-5 "Direct link to Improvement")

- Allow user to override `poll_interval` and `idle_connection_timeout` settings on connection. [#6230](https://github.com/ClickHouse/ClickHouse/pull/6230) ([alexey-milovidov](https://github.com/alexey-milovidov))

### ClickHouse Release 19.11.5.28, 2019-08-05[​](#clickhouse-release-19-11-5-28-2019-08-05 "Direct link to ClickHouse Release 19.11.5.28, 2019-08-05")

#### Bug Fix[​](#bug-fix-19 "Direct link to Bug Fix")

- Fixed the possibility of hanging queries when server is overloaded. [#6301](https://github.com/ClickHouse/ClickHouse/pull/6301) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fix FPE in yandexConsistentHash function. This fixes [#6304](https://github.com/ClickHouse/ClickHouse/issues/6304). [#6126](https://github.com/ClickHouse/ClickHouse/pull/6126) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fixed bug in conversion of `LowCardinality` types in `AggregateFunctionFactory`. This fixes [#6257](https://github.com/ClickHouse/ClickHouse/issues/6257). [#6281](https://github.com/ClickHouse/ClickHouse/pull/6281) ([Nikolai Kochetov](https://github.com/KochetovNicolai))
- Fix parsing of `bool` settings from `true` and `false` strings in configuration files. [#6278](https://github.com/ClickHouse/ClickHouse/pull/6278) ([alesapin](https://github.com/alesapin))
- Fix rare bug with incompatible stream headers in queries to `Distributed` table over `MergeTree` table when part of `WHERE` moves to `PREWHERE`. [#6236](https://github.com/ClickHouse/ClickHouse/pull/6236) ([alesapin](https://github.com/alesapin))
- Fixed overflow in integer division of signed type to unsigned type. This fixes [#6214](https://github.com/ClickHouse/ClickHouse/issues/6214). [#6233](https://github.com/ClickHouse/ClickHouse/pull/6233) ([alexey-milovidov](https://github.com/alexey-milovidov))

#### Backward Incompatible Change[​](#backward-incompatible-change-5 "Direct link to Backward Incompatible Change")

- `Kafka` still broken.

### ClickHouse Release 19.11.4.24, 2019-08-01[​](#clickhouse-release-19-11-4-24-2019-08-01 "Direct link to ClickHouse Release 19.11.4.24, 2019-08-01")

#### Bug Fix[​](#bug-fix-20 "Direct link to Bug Fix")

- Fix bug with writing secondary indices marks with adaptive granularity. [#6126](https://github.com/ClickHouse/ClickHouse/pull/6126) ([alesapin](https://github.com/alesapin))
- Fix `WITH ROLLUP` and `WITH CUBE` modifiers of `GROUP BY` with two-level aggregation. [#6225](https://github.com/ClickHouse/ClickHouse/pull/6225) ([Anton Popov](https://github.com/CurtizJ))
- Fixed hang in `JSONExtractRaw` function. Fixed [#6195](https://github.com/ClickHouse/ClickHouse/issues/6195) [#6198](https://github.com/ClickHouse/ClickHouse/pull/6198) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fix segfault in ExternalLoader::reloadOutdated(). [#6082](https://github.com/ClickHouse/ClickHouse/pull/6082) ([Vitaly Baranov](https://github.com/vitlibar))
- Fixed the case when server may close listening sockets but not shutdown and continue serving remaining queries. You may end up with two running clickhouse-server processes. Sometimes, the server may return an error `bad_function_call` for remaining queries. [#6231](https://github.com/ClickHouse/ClickHouse/pull/6231) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fixed useless and incorrect condition on update field for initial loading of external dictionaries via ODBC, MySQL, ClickHouse and HTTP. This fixes [#6069](https://github.com/ClickHouse/ClickHouse/issues/6069) [#6083](https://github.com/ClickHouse/ClickHouse/pull/6083) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fixed irrelevant exception in cast of `LowCardinality(Nullable)` to not-Nullable column in case if it does not contain Nulls (e.g. in query like `SELECT CAST(CAST('Hello' AS LowCardinality(Nullable(String))) AS String)`. [#6094](https://github.com/ClickHouse/ClickHouse/issues/6094) [#6119](https://github.com/ClickHouse/ClickHouse/pull/6119) ([Nikolai Kochetov](https://github.com/KochetovNicolai))
- Fix non-deterministic result of "uniq" aggregate function in extreme rare cases. The bug was present in all ClickHouse versions. [#6058](https://github.com/ClickHouse/ClickHouse/pull/6058) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Segfault when we set a little bit too high CIDR on the function `IPv6CIDRToRange`. [#6068](https://github.com/ClickHouse/ClickHouse/pull/6068) ([Guillaume Tassery](https://github.com/YiuRULE))
- Fixed small memory leak when server throw many exceptions from many different contexts. [#6144](https://github.com/ClickHouse/ClickHouse/pull/6144) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Fix the situation when consumer got paused before subscription and not resumed afterwards. [#6075](https://github.com/ClickHouse/ClickHouse/pull/6075) ([Ivan](https://github.com/abyss7)) Note that Kafka is broken in this version.
- Clearing the Kafka data buffer from the previous read operation that was completed with an error [#6026](https://github.com/ClickHouse/ClickHouse/pull/6026) ([Nikolay](https://github.com/bopohaa)) Note that Kafka is broken in this version.
- Since `StorageMergeTree::background_task_handle` is initialized in `startup()` the `MergeTreeBlockOutputStream::write()` may try to use it before initialization. Just check if it is initialized. [#6080](https://github.com/ClickHouse/ClickHouse/pull/6080) ([Ivan](https://github.com/abyss7))

#### Build/Testing/Packaging Improvement[​](#buildtestingpackaging-improvement-6 "Direct link to Build/Testing/Packaging Improvement")