From: | Chris Mair <list(at)1006(dot)org> |
---|---|
To: | Alvaro Herrera <alvherre(at)commandprompt(dot)com> |
Cc: | Luke Lonergan <llonergan(at)greenplum(dot)com>, pgsql-performance(at)postgresql(dot)org, markir(at)paradise(dot)net(dot)nz, Josh Berkus <josh(at)agliodbs(dot)com> |
Subject: | Re: bad performance on Solaris 10 |
Date: | 2006-04-05 23:13:55 |
Message-ID: | 1144278835.5133.11.camel@dell.home.lan |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-performance |
> > > 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!
Ok, so I could quite believe my own benchmarks and I decided
to do a fresh initdb and retry everything.
At first it looked like I coudn't reproduce the speed up I just saw.
Then I realized it was the
wal_sync_method = fsync
line that makes all the difference!
Normally parameters that are commented are default values, but for
wal_sync_method it actually says (note the comment):
wal_sync_method = fsync # the default is the first option
# supported by the operating system:
# open_datasync
# fdatasync
# fsync
# fsync_writethrough
# open_sync
So Im my last mail I drew the wrong conclusion, because i didn't comment
wal_sync_method to double check.
To the point: the default wal_sync_method choosen on Solaris 10 appears
to be a very bad one - for me, picking fsync increases performance ~
times 7, all other parameters unchanged!
Would it be a good idea to change this in the default install?
Bye, Chris.
PS: yes I did a fresh initdb again to double check ;)
From | Date | Subject | |
---|---|---|---|
Next Message | Mark Kirkwood | 2006-04-05 23:25:36 | Re: bad performance on Solaris 10 |
Previous Message | Tom Lane | 2006-04-05 22:24:47 | Re: Sun Fire T2000 and PostgreSQL 8.1.3 |