Sets the query cost above which JIT compilation attempts to inline functions and operators.
At a glance
| Property | Value |
|---|---|
| Parameter | jit_inline_above_cost |
| Category | Query Planning |
| Default | 500000 |
| Value type | floating point |
| Change scope | Per-session (SET) |
| Available in | PostgreSQL 12, 13, 14, 15, 16, 17, 18, 19 (added in 12) |
What it does
Sets the query cost above which JIT compilation attempts to inline functions and operators. Inlining adds planning time, but can improve execution speed. It is not meaningful to set this to less than jit_above_cost. Setting this to -1 disables inlining. The default is 500000.
(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 jit_inline_above_cost; or SELECT name, setting, unit, context, source FROM pg_settings WHERE name = 'jit_inline_above_cost';.
Tuning guidance
Increase it to suppress inlining on mid-cost queries where compile time outweighs the benefit; -1 disables inlining. Tune only after confirming JIT itself is worthwhile.