Asynchronous IO in Postgres 18 TL;DR

Postgres 18 just dropped with a bunch of goodies—UUIDv7, an “Over explain” module, composite index skip scans—and, most notably, built-in asynchronous IO. In this episode of The Backend Engineering Show, Hussein kicks off by contrasting sync vs. async calls, revisits how Postgres 17 handled synchronous IO, then digs into the new async world in v18.

The heart of the update is two async IO modes:

• worker: offloads IO to background threads
• io_uring: taps into Linux’s ring buffer interface

You still have a sync fallback, and the team’s already talking about future improvements (better backend-writer support, direct IO, etc.). Plus, there’s a handy timestamped rundown so you can skip straight to whatever you’re most curious about.

Watch on YouTube