Total parallel workers available cluster-wide.
At a glance
| Property | Value |
|---|---|
| Parameter | max_parallel_workers |
| Category | Parallelism |
| Default | 8 |
| Value type | boolean / enum / numeric |
| Change scope | Per-session (SET) |
What it does
Maximum number of workers the system supports for parallel queries, drawn from the max_worker_processes pool.
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 max_parallel_workers; or SELECT name, setting, unit, context, source FROM pg_settings WHERE name = 'max_parallel_workers';.
Tuning guidance
Set near your core count for analytics boxes. Ensure max_worker_processes is large enough to also cover background workers and logical replication.