Date: Thu, 8 Mar 2007 09:48:23 +0100
From: Magnus Hagander <magnus@hagander.net>
To: James Mansion <james@mansionfamily.plus.com>
Cc: Ron <rjpeace@earthlink.net>, pgsql-performance@postgresql.org
Subject: Re: compact flash disks?
Message-ID: <20070308084823.GA7216@svr2.hagander.net>
References: <E1HOxqf-0005Mn-Uw@elasmtp-kukur.atl.sa.earthlink.net>
	<HCEPKPMCAJLDGJIBCLGHOEDCHEAA.james@mansionfamily.plus.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <HCEPKPMCAJLDGJIBCLGHOEDCHEAA.james@mansionfamily.plus.com>
User-Agent: Mutt/1.5.11

On Thu, Mar 08, 2007 at 06:24:35AM -0000, James Mansion wrote:
> 
> In the long run, we are going to have to seriously rethink pg's use
> of WAL as the way we implement MVCC as it becomes more and more of a
> performance bottleneck.
> We have WAL because Stonebreaker made an assumption about the future
> dominance of optical media that has turned out to be false.
> ...and it's been one of pg's big issues every since.

Uh. pg didn't *have* WAL back when Stonebreaker was working on it. It
was added in PostgreSQL 7.1, by Vadim. And it significantly increased 
performance at the time, since we no longer had to sync the datafiles 
after every transaction commit.
(We also didn't have MVCC back in the Stonebreaker days - it was added
in 6.5)

That said, it's certainly possible that someone can find an even better
way to do it :-)

//Magnus