question about parallel. i read document and i can't solve it. provide the solution please.
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
On Sunday, November 9, 2025, PG Doc comments form <noreply@postgresql.org>
wrote:
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.
This is not the right place to seek support. We have a -general mailing
list for that.
How can I increase the Workers Launched value to match the Workers Planned
value, or at least raise it to 4?
That level of control is not provided.
I want to use parallel to speed up for index creation and data insertion
This page clearly states that data writing is not parallelized.
David J.