From: Kevin Brown <blargity@gmail.com>
To: Madison Kelly <linux@alteeve.com>
To: 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
Message-ID: <200512212044.53501.blargity@gmail.com> (raw)
In-Reply-To: <20051222021418.GB6026@ns.snowman.net>
References: <43AA0966.6090401@alteeve.com>
<20051222021418.GB6026@ns.snowman.net>
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.
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To: pgsql-performance@postgresql.org
Cc: blargity@gmail.com, linux@alteeve.com
Subject: Re: MySQL is faster than PgSQL but a large margin in my program... any ideas why?
In-Reply-To: <200512212044.53501.blargity@gmail.com>
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