Re: pg_restore -j

On Thu, Sep 17, 2009 at 12:12 PM, Joshua D. Drake <jd(at)commandprompt(dot)com> wrote:
> On Thu, 2009-09-17 at 12:05 -0600, Scott Marlowe wrote:
>> On Thu, Sep 17, 2009 at 12:00 PM, Joshua D. Drake <jd(at)commandprompt(dot)com> wrote:
>> > On Thu, 2009-09-17 at 11:48 -0600, Scott Marlowe wrote:
>> >> I'm trying to do a parallel restore with pg_restore -j but I'm only
>> >> seeing one CPU being used really.   The file is custom format, but was
>> >> made by pg_dump for pgsql 8.3.  Is that a problem? Do I need a backup
>> >> made with 8.4 to run parallel restore?
>> >
>> > Yes I believe but I don't recall. You could dump the TOC and note
>> > differences.
>>
>> I kinda figured, I'm making a dump with pg84 now to test with.  I'm
>> really hoping for a noticeable improvement in restore times, as we're
>> in the 1.5 to 2 hour range right now.
>>
>
> If you have the concurrency and disk IO, you should get that down below
> 30 minutes.

On our two big servers we have 12 Disk RAID-10 for pgdata, and 2 disk
RAID-1 for pg_xlog, and 8 cores. What's a good -j number to start at
there? I'm leaning towards 8 or 10 or 12 for testing. Woohoo late
night testing. :)