Waiting for Postgres 18: Accelerating Disk Reads with Asynchronous I/O

With the Postgres 18 Beta 1 release this week a multi-year effort, and significant architectural shift in Postgres is taking shape: Asynchronous I/O (AIO). These capabilities are still under active development, but they represent a fundamental change in how Postgres handles I/O, offering the potential for significant performance gains, particularly in cloud environments where latency is often the bottleneck. While some features may still be adjusted or dropped during the beta period before the final release, now is the best time to test and validate how Postgres 18 performs in practice. In Postgres 18 AIO is limited to read operations; writes remain synchronous, though support may expand in future versions. In this post, we explain what asynchronous I/O is, how it works in Postgres 18, and what it means for performance optimization. Why asynchronous I/O matters Postgres has historically operated under a synchronous I/O model, meaning every read request is a blocking system call. Th ... Read full article.