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

[Scott Marlowe <scott.marlowe@xxxxxxxxx>]

On Fri, May 1, 2015 at 9:16 AM, Susan K. McClure <smcclure@xxxxxxxx> 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.