Async I/O in PostgreSQL 18: Storage Finally Matters Again
April 21–22
Postgres 18 adds native support for asynchronous I/O. This is the most significant change in the I/O subsystem in decades. Instead of blocking on reads, Postgres can now issue I/O requests and continue working, aligning the database engine with how modern storage actually works.
We will see what async I/O means in PostgreSQL and how it affects performance across different storage backends, such as local and remote NVMe storage options, different cloud block storage solutions, and the comparisons between synchronous and asynchronous I/O operations. Additionally, we’ll investigate changes to CPU efficiency, concurrency, and tail latency across all of them.
Lastly, we discuss the benefits and drawbacks, when to use async I/O, and how to unlock the power of Postgres in modern infrastructure.