### ClickHouse release v20.8.16.20-lts FIXME as compared to v20.8.15.11-lts

#### Bug Fix
* Backported in [#22091](https://github.com/ClickHouse/ClickHouse/issues/22091): In case if query has constant `WHERE` condition, and setting `optimize_skip_unused_shards` enabled, all shards may be skipped and query could return incorrect empty result. [#21550](https://github.com/ClickHouse/ClickHouse/pull/21550) ([Amos Bird](https://github.com/amosbird)).
* Backported in [#22049](https://github.com/ClickHouse/ClickHouse/issues/22049): Fix deadlock in first catboost model execution. Closes [#13832](https://github.com/ClickHouse/ClickHouse/issues/13832). [#21844](https://github.com/ClickHouse/ClickHouse/pull/21844) ([Kruglov Pavel](https://github.com/Avogar)).