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* Add Comments for set index functions. [#6319](https://github.com/yandex/ClickHouse/pull/6319) ([Nikita Vasilev](https://github.com/nikvas0)) * Add Comments for set index functions. [#6319](https://github.com/yandex/ClickHouse/pull/6319) ([Nikita Vasilev](https://github.com/nikvas0))
### Performance Improvement ### Performance Improvement
* Optimize queries with `ORDER BY expressions` clause, where `expressions` have coinciding prefix with sorting key in `MergeTree` tables. This optimization is enabled with `optimize_read_in_order` setting. [#6054](https://github.com/yandex/ClickHouse/pull/6054) [#6629](https://github.com/yandex/ClickHouse/pull/6629) ([Anton Popov](https://github.com/CurtizJ)) * Optimize queries with `ORDER BY expressions` clause, where `expressions` have coinciding prefix with sorting key in `MergeTree` tables. This optimization is controlled by `optimize_read_in_order` setting. [#6054](https://github.com/yandex/ClickHouse/pull/6054) [#6629](https://github.com/yandex/ClickHouse/pull/6629) ([Anton Popov](https://github.com/CurtizJ))
* Implemented batch variant of updating aggregate function states. It may lead to performance benefits. [#6435](https://github.com/yandex/ClickHouse/pull/6435) ([alexey-milovidov](https://github.com/alexey-milovidov)) * Implemented batch variant of updating aggregate function states. It may lead to performance benefits. [#6435](https://github.com/yandex/ClickHouse/pull/6435) ([alexey-milovidov](https://github.com/alexey-milovidov))
* Using `FastOps` library for functions `exp`, `log`, `sigmoid`, `tanh`. FastOps is a fast vector math library from Michael Parakhin (Yandex CTO). Improved performance of `exp` and `log` functions more than 6 times. The functions `exp` and `log` from `Float32` argument will return `Float32` (in previous versions they always return `Float64`). Now `exp(nan)` may return `inf`. The result of `exp` and `log` functions may be not the nearest machine representable number to the true answer. [#6254](https://github.com/yandex/ClickHouse/pull/6254) ([alexey-milovidov](https://github.com/alexey-milovidov)) * Using `FastOps` library for functions `exp`, `log`, `sigmoid`, `tanh`. FastOps is a fast vector math library from Michael Parakhin (Yandex CTO). Improved performance of `exp` and `log` functions more than 6 times. The functions `exp` and `log` from `Float32` argument will return `Float32` (in previous versions they always return `Float64`). Now `exp(nan)` may return `inf`. The result of `exp` and `log` functions may be not the nearest machine representable number to the true answer. [#6254](https://github.com/yandex/ClickHouse/pull/6254) ([alexey-milovidov](https://github.com/alexey-milovidov))
* Disable consecutive key optimization for `UInt8/16`. [#6298](https://github.com/yandex/ClickHouse/pull/6298) [#6701](https://github.com/yandex/ClickHouse/pull/6701) ([akuzm](https://github.com/akuzm)) * Disable consecutive key optimization for `UInt8/16`. [#6298](https://github.com/yandex/ClickHouse/pull/6298) [#6701](https://github.com/yandex/ClickHouse/pull/6701) ([akuzm](https://github.com/akuzm))