DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com;
	h=received:from:to:subject:date:user-agent:references:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:message-id;
	b=FQnFHQKg+0ICvLzLZttpuHmQFR4VRVcmFxIqVJLFkokBpLfWh7I+LSkWvYpgUc8xg69+jiSD3OyO6epfqOfkgDgH27o0ABbvtpW9FyDpYn8Hk7OAImCWLQqMWddtlMjMMKiXd7CClskXzz9/igxt0cO/AtcAxIYK+4UEOlNQN1A=
From: Kevin Brown <blargity@gmail.com>
To: Madison Kelly <linux@alteeve.com>,
 pgsql-performance@postgresql.org
Subject: Re: MySQL is faster than PgSQL but a large margin in my program...
	any ideas why?
Date: Wed, 21 Dec 2005 20:44:53 -0600
User-Agent: KMail/1.8
References: <43AA0966.6090401@alteeve.com>
	<20051222021418.GB6026@ns.snowman.net>
In-Reply-To: <20051222021418.GB6026@ns.snowman.net>
MIME-Version: 1.0
Content-Type: text/plain;
  charset="utf-8"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-Id: <200512212044.53501.blargity@gmail.com>

On Wednesday 21 December 2005 20:14, Stephen Frost wrote:
> * Madison Kelly (linux@alteeve.com) wrote:
> >   If the performace difference comes from the 'COPY...' command being
> > slower because of the automatic quoting can I somehow tell PostgreSQL
> > that the data is pre-quoted? Could the performance difference be
> > something else?
>
> I doubt the issue is with the COPY command being slower than INSERTs
> (I'd expect the opposite generally, actually...).  What's the table type
> of the MySQL tables?  Is it MyISAM or InnoDB (I think those are the main
> alternatives)?  IIRC, MyISAM doesn't do ACID and isn't transaction safe,
> and has problems with data reliability (aiui, equivilant to doing 'fsync
> = false' for Postgres).  InnoDB, again iirc, is transaction safe and
> whatnot, and more akin to the default PostgreSQL setup.
>
> I expect some others will comment along these lines too, if my response
> isn't entirely clear. :)

Is fsync() on in your postgres config?  If so, that's why you're slower.  The 
default is to have it on for stability (writes are forced to disk).  It is 
quite a bit slower than just allowing the write caches to do their job, but 
more stable.  MySQL does not force writes to disk.