User-Agent: Microsoft-Entourage/10.1.4.030702.0
Date: Wed, 15 Oct 2003 01:26:08 -0700
Subject: Re: Database Kernels and O_DIRECT
From: James Rogers <jamesr@best.com>
To: <pgsql-hackers@postgresql.org>
Message-ID: <BBB252B0.5B3F%jamesr@best.com>
In-Reply-To: <BBB237C0.5B35%jamesr@best.com>
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On 10/14/03 11:31 PM, "James Rogers" <jamesr@best.com> wrote:
> 
> There is some abstraction in Postgres and the database is well-written, but
> it isn't written in a manner that makes it easy to swap out operating system
> or API models.  It is written to be portable at all levels.  A database
> kernel isn't necessarily required to be portable at the very lowest level,
> but it is vastly more optimizable because you aren't forced into a narrow
> set of choices for interfacing with the operating system.


Just to clarify, my post wasn't really to say that we should run out and
make Postgres use a database kernel type internal model tomorrow.  The point
of all that was that Oracle does things that way for a very good reason and
that there can be benefits that may not be immediately obvious.

It is really one of those emergent "needs" when a database engine gets to a
certain level of sophistication.  For smaller and simpler databases, you
don't really need it and the effort isn't justified.  At some point, you
cross a threshold where not only does it become justified but it becomes a
wise idea or not having it will start to punish you in a number of different
ways.  I personally think that Postgres is sitting on the cusp of "its a
wise idea", and that it is something worth thinking about in the future.

Cheers,

-James Rogers
 jamesr@best.com