On 28 June 2012 19:25, Kevin Grittner <Kevin.Grittner@wicourts.gov> wrote:
> Peter Geoghegan <peter@2ndquadrant.com> wrote:
>
>> Is anyone aware of a non-zero commit_delay in the wild today? I
>> personally am not.
>
> http://archives.postgresql.org/pgsql-performance/2011-11/msg00083.php
In that thread, Robert goes on to say to the OP that has set commit_delay:
>On Fri, Nov 4, 2011 at 2:45 PM, Claudio Freire <klaussfreire@gmail.com> wrote:
>> I don't think 1 second can be such a big difference for the bgwriter,
>> but I might be wrong.
>
> Well, the default value is 200 ms. And I've never before heard of
> anyone tuning it up, except maybe to save on power consumption on a
> system with very low utilization. Nearly always you want to reduce
> it.
>
>> The wal_writer makes me doubt, though. If logged activity was higher
>> than 8MB/s, then that setting would block it all.
>> I guess I really should lower it.
>
> Here again, you've set it to ten times the default value. That
> doesn't seem like a good idea. I would start with the default and
> tune down.
So, let me rephrase my question: Is anyone aware of a non-zero
commit_delay in the wild today with sensible reasoning behind it?
--
Peter Geoghegan http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training and Services