Collect timing of block read/write operations.
At a glance
| Property | Value |
|---|---|
| Parameter | track_io_timing |
| Category | Statistics |
| Default | off |
| Value type | boolean / enum / numeric |
| Change scope | Superuser / reload |
What it does
When on, times each I/O operation, populating block-read/write timing in pg_stat_database and EXPLAIN (ANALYZE, BUFFERS).
How to apply a change
Can be changed at runtime by a superuser for the current session, or globally via reload.
Inspect the current value and source with SHOW track_io_timing; or SELECT name, setting, unit, context, source FROM pg_settings WHERE name = 'track_io_timing';.
Tuning guidance
Turn on if your platform has a low-overhead clock (test with pg_test_timing). It makes EXPLAIN show real I/O time, invaluable for tuning.