From: Chris Mair <list@1006.org>
To: pgsql-performance@postgresql.org
Cc: markir@paradise.net.nz
Cc: josh@agliodbs.com
Cc: llonergan@greenplum.com
Subject: Re: bad performance on Solaris 10
Date: Wed, 05 Apr 2006 23:31:25 +0200
Message-ID: <1144272685.4562.43.camel@dell.home.lan> (raw)
In-Reply-To: <1144111178.3723.80.camel@dell.home.lan>
References: <1144111178.3723.80.camel@dell.home.lan>
Hi,
thanks for all replys.
I've done a few tests.
Remounting the fs where $PGDATA lives with "forcedirectio"
(together with logging, that is default) did not help
(if not harm...) 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!
Playing around with these modifications I find that it's
actually just the
wal_buffers = 128
alone which makes all the difference!
Quickly playing around with wal_buffers on Linux and Mac OS X
I see it influences the performance of my test a bit, maybe in the
10-20% range (I'm really doing quick tests, nothing systematic),
but nowhere near as spectacularly as on Solaris.
I'm happy so far, but I find it very surprising that this single
parameter has such an impact (only on) Solaris 10.
(my test program is a bulk inserts using PQputCopyData in large
transactions - all test were 8.1.3).
Bye, Chris
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To: pgsql-performance@postgresql.org
Cc: list@1006.org, markir@paradise.net.nz, josh@agliodbs.com, llonergan@greenplum.com
Subject: Re: bad performance on Solaris 10
In-Reply-To: <1144272685.4562.43.camel@dell.home.lan>
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