From: Bruce Momjian <pgman@candle.pha.pa.us>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Michael Fuhr <mike@fuhr.org>
Cc: Merlin Moncure <merlin.moncure@rcsonline.com>
Cc: pgsql-performance@postgresql.org, Carlos Benkendorf <carlosbenkendorf@yahoo.com.br>
Subject: Re: How much expensive are row level statistics?
Date: Fri, 16 Dec 2005 21:44:19 -0500 (EST)
Message-ID: <200512170244.jBH2iJV11094@candle.pha.pa.us> (raw)
In-Reply-To: <1667.1134444045@sss.pgh.pa.us>
Tom Lane wrote:
> Michael Fuhr <mike@fuhr.org> writes:
> > Further tests show that for this application
> > the killer is stats_command_string, not stats_block_level or
> > stats_row_level.
>
> I tried it with pgbench -c 10, and got these results:
> 41% reduction in TPS rate for stats_command_string
Woh, 41%. That's just off the charts! What are we doing internally
that would cause that?
--
Bruce Momjian | http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
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To: pgsql-performance@postgresql.org
Cc: pgman@candle.pha.pa.us, tgl@sss.pgh.pa.us, mike@fuhr.org, merlin.moncure@rcsonline.com, carlosbenkendorf@yahoo.com.br
Subject: Re: How much expensive are row level statistics?
In-Reply-To: <200512170244.jBH2iJV11094@candle.pha.pa.us>
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