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. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html