title_wip

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

- JOIN filter push down improvements using equivalent sets. [#61216](https://github.com/ClickHouse/ClickHouse/pull/61216) ([Maksim Kita](https://github.com/kitaisreal)).
- Convert OUTER JOIN to INNER JOIN optimization if the filter after JOIN always filters default values. Optimization can be controlled with setting `query_plan_convert_outer_join_to_inner_join`, enabled by default. [#62907](https://github.com/ClickHouse/ClickHouse/pull/62907) ([Maksim Kita](https://github.com/kitaisreal)).
- Improvement for AWS S3. Client has to send header 'Keep-Alive: timeout=X' to the server. If a client receives a response from the server with that header, client has to use the value from the server. Also for a client it is better not to use a connection which is nearly expired in order to avoid connection close race. [#62249](https://github.com/ClickHouse/ClickHouse/pull/62249) ([Sema Checherinda](https://github.com/CheSema)).
- Reduce overhead of the mutations for SELECTs (v2). [#60856](https://github.com/ClickHouse/ClickHouse/pull/60856) ([Azat Khuzhin](https://github.com/azat)).
- More frequently invoked functions in PODArray are now force-inlined. [#61144](https://github.com/ClickHouse/ClickHouse/pull/61144) ([李扬](https://github.com/taiyang-li)).
- Speed up parsing of JSON by skipping the rest of the object when all required columns are read. [#62210](https://github.com/ClickHouse/ClickHouse/pull/62210) ([lgbo](https://github.com/lgbo-ustc)).
- Improve trivial insert select from files in file/s3/hdfs/url/... table functions. Add separate max\_parsing\_threads setting to control the number of threads used in parallel parsing. [#62404](https://github.com/ClickHouse/ClickHouse/pull/62404) ([Kruglov Pavel](https://github.com/Avogar)).
- Functions `to_utc_timestamp` and `from_utc_timestamp` are now about 2x faster. [#62583](https://github.com/ClickHouse/ClickHouse/pull/62583) ([KevinyhZou](https://github.com/KevinyhZou)).
- Functions `parseDateTimeOrNull`, `parseDateTimeOrZero`, `parseDateTimeInJodaSyntaxOrNull` and `parseDateTimeInJodaSyntaxOrZero` now run significantly faster (10x - 1000x) when the input contains mostly non-parseable values. [#62634](https://github.com/ClickHouse/ClickHouse/pull/62634) ([LiuNeng](https://github.com/liuneng1994)).
- SELECTs against `system.query_cache` are now noticeably faster when the query cache contains lots of entries (e.g. more than 100.000). [#62671](https://github.com/ClickHouse/ClickHouse/pull/62671) ([Robert Schulze](https://github.com/rschu1ze)).
- Less contention in filesystem cache (part 3): execute removal from filesystem without lock on space reservation attempt. [#61163](https://github.com/ClickHouse/ClickHouse/pull/61163) ([Kseniia Sumarokova](https://github.com/kssenii)).
- Speed up dynamic resize of filesystem cache. [#61723](https://github.com/ClickHouse/ClickHouse/pull/61723) ([Kseniia Sumarokova](https://github.com/kssenii)).
- Dictionary source with `INVALIDATE_QUERY` is not reloaded twice on startup. [#62050](https://github.com/ClickHouse/ClickHouse/pull/62050) ([vdimir](https://github.com/vdimir)).
- Fix an issue where when a redundant `= 1` or `= 0` is added after a boolean expression involving the primary key, the primary index is not used. For example, both `SELECT * FROM <table> WHERE <primary-key> IN (<value>) = 1` and `SELECT * FROM <table> WHERE <primary-key> NOT IN (<value>) = 0` will both perform a full table scan, when the primary index can be used. [#62142](https://github.com/ClickHouse/ClickHouse/pull/62142) ([josh-hildred](https://github.com/josh-hildred)).
- Return stream of chunks from `system.remote_data_paths` instead of accumulating the whole result in one big chunk. This allows to consume less memory, show intermediate progress and cancel the query. [#62613](https://github.com/ClickHouse/ClickHouse/pull/62613) ([Alexander Gololobov](https://github.com/davenger)).

#### Experimental Feature[​](#experimental-feature-6 "Direct link to Experimental Feature")

- Support parallel write buffer for Azure Blob Storage managed by setting `azure_allow_parallel_part_upload`. [#62534](https://github.com/ClickHouse/ClickHouse/pull/62534) ([SmitaRKulkarni](https://github.com/SmitaRKulkarni)).
- Userspace page cache works with static web storage (`disk(type = web)`) now. Use client setting `use_page_cache_for_disks_without_file_cache=1` to enable. [#61911](https://github.com/ClickHouse/ClickHouse/pull/61911) ([Michael Kolupaev](https://github.com/al13n321)).
- Don't treat Bool and number variants as suspicious in the `Variant` type. [#61999](https://github.com/ClickHouse/ClickHouse/pull/61999) ([Kruglov Pavel](https://github.com/Avogar)).
- Implement better conversion from String to `Variant` using parsing. [#62005](https://github.com/ClickHouse/ClickHouse/pull/62005) ([Kruglov Pavel](https://github.com/Avogar)).
- Support `Variant` in JSONExtract functions. [#62014](https://github.com/ClickHouse/ClickHouse/pull/62014) ([Kruglov Pavel](https://github.com/Avogar)).
- Mark type `Variant` as comparable so it can be used in primary key. [#62693](https://github.com/ClickHouse/ClickHouse/pull/62693) ([Kruglov Pavel](https://github.com/Avogar)).

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