v.19.3Improvements

Implemented AIO Support for Freebsd

Implemented AIO support for FreeBSD. #4305 (urgordeadbeef)
Implemented asynchronous I/O (AIO) support for FreeBSD in ClickHouse.

Why it matters

This feature enables ClickHouse to use asynchronous I/O on FreeBSD systems, improving I/O performance and efficiency by allowing non-blocking disk operations. It resolves the lack of native AIO support on FreeBSD, thus enhancing ClickHouse usability and performance on this platform.

How to use it

Users on FreeBSD platforms can benefit from asynchronous I/O support automatically when running ClickHouse with this version. No special configuration is required beyond the usual ClickHouse deployment on FreeBSD.