From: Tom Lane <tgl@sss.pgh.pa.us>
To: Jignesh K. Shah <J.K.Shah@Sun.COM>
Cc: Josh Berkus <josh@agliodbs.com>
Cc: pgsql-performance@postgresql.org, Gregory Stark <stark@enterprisedb.com>
Cc: pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] 8.3beta1 testing on Solaris
Date: Fri, 26 Oct 2007 15:08:16 -0400
Message-ID: <24692.1193425696@sss.pgh.pa.us> (raw)
In-Reply-To: <472219D6.6030001@sun.com>
References: <4720FB72.8060800@sun.com>
<871wbi95nb.fsf@oxford.xeocode.com>
<29721.1193359867@sss.pgh.pa.us>
<200710251956.56744.josh@agliodbs.com>
<2139.1193369168@sss.pgh.pa.us>
<4721ED75.7090607@sun.com>
<47220B96.4080009@sun.com>
<472219D6.6030001@sun.com>
"Jignesh K. Shah" <J.K.Shah@Sun.COM> writes:
> So the ratio of reads vs writes to clog files is pretty huge..
It looks to me that the issue is simply one of not having quite enough
CLOG buffers. Your first run shows 8 different pages being fetched and
the second shows 10. Bearing in mind that we "pin" the latest CLOG page
into buffers, there are only NUM_CLOG_BUFFERS-1 buffers available for
older pages, so what we've got here is thrashing for the available
slots.
Try increasing NUM_CLOG_BUFFERS to 16 and see how it affects this test.
regards, tom lane
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, J.K.Shah@Sun.COM, josh@agliodbs.com, stark@enterprisedb.com, pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] 8.3beta1 testing on Solaris
In-Reply-To: <24692.1193425696@sss.pgh.pa.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox