Planner cost of a sequential page fetch (the baseline).
At a glance
| Property | Value |
|---|---|
| Parameter | seq_page_cost |
| Category | Query Planner |
| Default | 1.0 |
| Value type | boolean / enum / numeric |
| Change scope | Per-session (SET) |
What it does
The reference cost (1.0) for reading one page in a sequential scan. All other cost parameters are relative to this.
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 seq_page_cost; or SELECT name, setting, unit, context, source FROM pg_settings WHERE name = 'seq_page_cost';.
Tuning guidance
Usually left at 1.0; adjust the ratio with random_page_cost instead.