Skip site navigation (1) Skip section navigation (2)

Re: Re: Faster CREATE DATABASE by delaying fsync (was 8.4.1 ubuntu karmic slow createdb)

From: david(at)lang(dot)hm
To: Greg Stark <gsstark(at)mit(dot)edu>
Cc: Andres Freund <andres(at)anarazel(dot)de>, pgsql-performance(at)postgresql(dot)org, pgsql-hackers(at)postgresql(dot)org, Michael Clemmons <glassresistor(at)gmail(dot)com>, Hannu Krosing <hannu(at)2ndquadrant(dot)com>, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>
Subject: Re: Re: Faster CREATE DATABASE by delaying fsync (was 8.4.1 ubuntu karmic slow createdb)
Date: 2009-12-29 00:30:17
Message-ID: alpine.DEB.2.00.0912281629150.24130@asgard.lang.hm (view raw or flat)
Thread:
Lists: pgsql-hackerspgsql-performance
On Tue, 29 Dec 2009, Greg Stark wrote:

> On Mon, Dec 28, 2009 at 10:54 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:
>> fsync everything in that pass.
>> Including the directory - which was not done before and actually might be
>> necessary in some cases.
>
> Er. Yes. At least on ext4 this is pretty important. I wish it weren't,
> but it doesn't look like we're going to convince the ext4 developers
> they're crazy any day soon and it would really suck for a database
> created from a template to have files in it go missin.

actually, as I understand it you need to do this on all filesystems except 
ext3, and on ext3 fsync is horribly slow because it writes out 
_everything_ that's pending, not just stuff related to the file you do the 
fsync on.

David Lang

In response to

Responses

pgsql-performance by date

Next:From: Andres FreundDate: 2009-12-29 00:43:15
Subject: Re: Re: Faster CREATE DATABASE by delaying fsync (was 8.4.1 ubuntu karmic slow createdb)
Previous:From: Andres FreundDate: 2009-12-29 00:29:34
Subject: Re: [HACKERS] Re: Faster CREATE DATABASE by delaying fsync (was 8.4.1 ubuntu karmic slow createdb)

pgsql-hackers by date

Next:From: Andres FreundDate: 2009-12-29 00:32:40
Subject: Re: parse tree to XML format
Previous:From: Andres FreundDate: 2009-12-29 00:29:34
Subject: Re: [HACKERS] Re: Faster CREATE DATABASE by delaying fsync (was 8.4.1 ubuntu karmic slow createdb)

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group