Selects the method for executing asynchronous I/O.
At a glance
| Property | Value |
|---|---|
| Parameter | io_method |
| Category | Resource Consumption |
| Default | (see documentation) |
| Value type | enum |
| Change scope | Per-session (SET) |
| Available in | PostgreSQL 18, 19 (added in 18) |
What it does
Selects the method for executing asynchronous I/O. Possible values are: worker (execute asynchronous I/O using worker processes)
io_uring (execute asynchronous I/O using io_uring, requires a build with –with-liburing / -Dliburing)
(Description quoted from the official PostgreSQL documentation.)
How to apply a change
Can be set per session with SET, per role/database with ALTER ROLE/DATABASE ... SET, or globally in postgresql.conf.
Inspect the current value and source with SHOW io_method; or SELECT name, setting, unit, context, source FROM pg_settings WHERE name = 'io_method';.
Tuning guidance
Leave at the platform default unless benchmarking; worker (async I/O workers) can help read-heavy scans on modern Linux, but verify with your own workload before changing it cluster-wide.