From: Brian Wipf <brian@clickspace.com>
To: pgsql-performance@postgresql.org
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Guido Neitzer <lists@event-s.net>
Cc: Brendan Duddridge <brendan@clickspace.com>
Cc: Jim C. Nasby <jim@nasby.net>
Subject: Re: shared_buffers > 284263 on OS X
Date: Tue, 5 Dec 2006 16:06:41 -0700
Message-ID: <FFB38162-AF10-452D-AFA1-B964F1E48B34@clickspace.com> (raw)
I wanted to post a follow up to the list regarding a high
shared_buffers value on OS X 10.4.8.
Thanks to Tom's help we successfully compiled PostgreSQL 8.1.5 using
64-bit on OS X Server 10.4.8 (You can find info. for this on pgports)
shared_buffers can now be set as high as shmmax without getting the
error message "could not create shared memory segment...". Now,
however, when shared_buffers are set greater than 279212 a
segmentation fault occurs on startup of PostgreSQL.
While trying to quantify the performance difference with higher
shared_buffers versus relying more on the kernel cache, the
difference does not appear as significant as I thought. We currently
have shared_buffers set to about 25% of system memory on our box
where we are free to set it within the bounds of shmmax (not OS X, of
course).
Brian Wipf
<brian@clickspace.com>
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To: pgsql-performance@postgresql.org
Cc: brian@clickspace.com, tgl@sss.pgh.pa.us, lists@event-s.net, brendan@clickspace.com, jim@nasby.net
Subject: Re: shared_buffers > 284263 on OS X
In-Reply-To: <FFB38162-AF10-452D-AFA1-B964F1E48B34@clickspace.com>
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