From: Chris Mair <list@1006.org>
To: pgsql-performance@postgresql.org
Subject: Re: bad performance on Solaris 10
Date: Thu, 06 Apr 2006 01:33:07 +0200
Message-ID: <1144279987.5133.22.camel@dell.home.lan> (raw)
In-Reply-To: <1144272685.4562.43.camel@dell.home.lan>
References: <1144111178.3723.80.camel@dell.home.lan>
<1144272685.4562.43.camel@dell.home.lan>
appears this didn't make it to the list... resending to the list
directly...
---
> > > 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 ;)
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To: pgsql-performance@postgresql.org
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Subject: Re: bad performance on Solaris 10
In-Reply-To: <1144279987.5133.22.camel@dell.home.lan>
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