Re: pg_dump and pg_restore with multiple streams does Not seem to improve overall times

On Fri, May 1, 2015 at 9:16 AM, Susan K. McClure <smcclure(at)rice(dot)edu> wrote:

> Running postgresql 9-4 on REHL 7 system. I am trying to speed up pg_dump
> and pg_restore by
> using a postgresql.conf with various performance options set, and the
> --jobs option to force multiple
> streams. But various tests, with various "--jobs=" numbers only achieve
> at most a 1 minute improvement
> in elapsed time versus doing pg_dump or pg_restore with no "--jobs" option
> and no postgresql.conf with performance
> options. Am I missing some key option(s) to improve things??
>
> The DB in question is ~25GB. The processor has 24 Cpus, 12 cores
>
> I have tried with "--jobs = 8, 12, and 20" with little or no discernible
> improvements.
>

So have you tried 2 jobs first? I'd see how 1, 2, 3, 4 etc work. See if 2
is faster than 1, then 3 faster than 2 etc.

Most of the time, unless you've got a really fast IO subsystem increasing
the --jobs doesn't make a big difference as a lot of the work is
sequential. Also on restores I think the extra jobs part only kicks in for
index builds.