Re: bad performance on Solaris 10

Luke Lonergan wrote:
> Chris,
>
> On 4/5/06 2:31 PM, "Chris Mair" <list@1006.org> wrote:
>
> > Doing what http://blogs.sun.com/roller/page/jkshah suggests:
> >   wal_sync_method = fsync (unchanged)
> >   wal_buffers = 128 (was 8)
> >   checkpoint_segments = 128 (was 3)
> >   bgwriter_all_percent = 0 (was 0.333)
> >   bgwriter_all_maxpages = 0 (was 5)
> > and leaving everything else default (solarispackages from pgfoundry)
> > increased performance ~ 7 times!
>
> In the recent past, Jignesh Shaw of Sun MDE discovered that changing the
> bgwriter_* parameters to zero had a dramatic positive impact on performance.

This essentially means stopping all bgwriter activity, thereby deferring
all I/O until checkpoint.  Was this considered?  With
checkpoint_segments to 128, it wouldn't surprise me that there wasn't
any checkpoint executed at all during the whole test ...

--
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.