From: Scott Marlowe <smarlowe@g2switchworks.com>
To: Merlin Moncure <mmoncure@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: yoav x <yoav112003@yahoo.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: sql-bench
Date: Wed, 13 Sep 2006 16:10:25 -0500
Message-ID: <1158181825.24726.4.camel@state.g2switchworks.com> (raw)
In-Reply-To: <b42b73150609131236y4132648csed2391b0b498f492@mail.gmail.com>
References: <20060913122414.16995.qmail@web35811.mail.mud.yahoo.com>
<12097.1158161568@sss.pgh.pa.us>
<b42b73150609131236y4132648csed2391b0b498f492@mail.gmail.com>
On Wed, 2006-09-13 at 14:36, Merlin Moncure wrote:
> On 9/13/06, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> > IIRC, with these settings PG 8.0 seemed to be about half the speed of
> > mysql 5.0 w/myisam, which is probably somewhere in the ballpark of the
> > truth for tests of this nature, ie, single query stream of fairly simple
> > queries. If you try concurrent-update scenarios or something that
> > stresses planning ability you may arrive at different results though.
> > I have not retested with more recent versions.
>
> if postgresql uses prepared statements for such queries, it will
> roughly tie mysql/myisam in raw query output on this type of load
> which also happens to be very easy to prepare...afaik mysql gets zero
> performance benefit from preparing statements This is extremely
> trivial to test&confirm even on a shell script. [aside: will this
> still be the case if peter e's planner changes become reality?]
>
> another cheater trick benchmarkers do to disparage postgresql is to
> not run analyze intentionally. Basically all production postgresql
> systems of any size will run analyze on cron.
>
> another small aside, I caught the sqlite people actually *detuning*
> postgresql for performance by turning stats_command_string=on in
> postgresql.conf. The way it was portrayed it almost looked like
> cheating. I busted them on it (go to
> http://www.sqlite.org/cvstrac/wiki?p=SpeedComparison and look for the
> remarks right below the results)
They're running autovacuum, which requires that, doesn't it?
I'd rather them be running autovacuum than not vacuuming / analyzing at
all. And autovacuum is a pretty realistic setting for most databases (I
use it on my production machines.)
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To: pgsql-performance@postgresql.org
Cc: smarlowe@g2switchworks.com, mmoncure@gmail.com, tgl@sss.pgh.pa.us, yoav112003@yahoo.com
Subject: Re: sql-bench
In-Reply-To: <1158181825.24726.4.camel@state.g2switchworks.com>
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