Re: [GENERAL] Performance while loading data and indexing

James Maes <jmaes@materialogic.com>

From: "James Maes" <jmaes@materialogic.com>
To: "Bruce Momjian" <pgman@candle.pha.pa.us>, "Neil Conway" <neilc@samurai.com>
Cc: <shridhar_daithankar@persistent.co.in>, <pgsql-hackers@postgresql.org>, <pgsql-general@postgresql.org>
Date: 2002-09-26T21:06:07Z
Lists: pgsql-hackers, pgsql-performance, pgsql-general
Has there been any thought of providing RAW disk support to bypass the fs?

-----Original Message-----
From: pgsql-hackers-owner@postgresql.org
[mailto:pgsql-hackers-owner@postgresql.org]On Behalf Of Bruce Momjian
Sent: Thursday, September 26, 2002 3:57 PM
To: Neil Conway
Cc: shridhar_daithankar@persistent.co.in; pgsql-hackers@postgresql.org;
pgsql-general@postgresql.org
Subject: Re: [HACKERS] [GENERAL] Performance while loading data and
indexing


Neil Conway wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > The paper does recommend ext3, but the differences between file systems
> > are very small.
>
> Well, I only did a very rough benchmark (a few runs of pgbench), but
> the results I found were drastically different: ext2 was significantly
> faster (~50%) than ext3-writeback, which was in turn significantly
> faster (~25%) than ext3-ordered.
>
> > Also, though ext3 is slower, turning fsync off should make ext3 function
> > similar to ext2.
>
> Why would that be?

OK, I changed the text to:

	File system choice is particularly difficult on Linux because there are
	so many file system choices, and none of them are optimal: ext2 is not
	entirely crash-safe, ext3, xfs, and jfs are journal-based, and Reiser is
	optimized for small files and does journalling. The journalling file
	systems can be significantly slower than ext2 but when crash recovery is
	required, ext2 isn't an option.

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