The following documentation comment has been logged on the website: Page: https://www.postgresql.org/docs/18/when-can-parallel-query-be-used.html Description:
I'm inquiring because I have some problem getting parallel processing to run effectively in PostgreSQL. My current parameter settings. max_parallel_apply_workers_per_subscription = 2 max_parallel_maintenance_workers = 8 max_parallel_workers = 8 max_parallel_workers_per_gather = 4 max_worker_processes = 8 We are using a 4core CPU. When I set the table's parallel_workers to 8 or use a hint like /* + Parallel (a 8) */, the EXPLAIN ANALYZE output shows: -> Gather immediately followed by Workers Planned: 8 and Workers Launched: 2. It seems the performance is not different when I use parallel because the Workers Launched value is only 2. How can I increase the Workers Launched value to match the Workers Planned value, or at least raise it to 4? I want to use parallel to speed up for index creation and data insertion
