Re: Parallel query execution introduces performance regressions

Hi,

Please don't top-quote on postgres mailing lists.

On 2019-04-01 15:08:59 -0400, Jinho Jung wrote:
> Sorry for the duplicated thread here and thanks for the reply.
> 
> I have another question regarding parallel execution. We noticed that
> PostgreSQL sometimes launches only one worker. Is that also an intended
> behavior?

Note that even a single worker is a form of parallelism - the "main"
backend also participates in query execution. So yes, that can be a
reasonable behaviour. Also, it might be that query was just finished
faster than a worker was able to launch.

- Andres