From: Tom Lane <tgl@sss.pgh.pa.us>
To: Greg Smith <gsmith@gregsmith.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Direct I/O issues
Date: Thu, 23 Nov 2006 11:45:42 -0500
Message-ID: <14171.1164300342@sss.pgh.pa.us> (raw)
In-Reply-To: <Pine.GSO.4.64.0611230013550.26031@westnet.com>
References: <Pine.GSO.4.64.0611230013550.26031@westnet.com>
Greg Smith <gsmith@gregsmith.com> writes:
> The results I get now look fishy.
There are at least two things wrong with this program:
* It does not respect the alignment requirement for O_DIRECT buffers
(reportedly either 512 or 4096 bytes depending on filesystem).
* It does not check for errors (if it had, you might have realized the
other problem).
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, gsmith@gregsmith.com
Subject: Re: Direct I/O issues
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