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

Re: Write ahead logging

From: Matthias Meixner <meixner(at)dvs1(dot)informatik(dot)tu-darmstadt(dot)de>
To: Mario Weilguni <mweilguni(at)sime(dot)com>
Cc: Manfred Koizar <mkoi-pg(at)aon(dot)at>, pgsql-performance(at)postgresql(dot)org
Subject: Re: Write ahead logging
Date: 2003-02-21 08:52:48
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-performance
Mario Weilguni wrote:
>>>So the question is: has anybody verified, that the log is written to disk
>>>before returning from commit?
>>Some (or all?) IDE disks are known to lie:  they report success as
>>soon as the data have reached the drive's RAM.
> under linux, hdparm -W can turn off the write cache of IDE disk, maybe you
> should try with write-caching turned off.

Yes, that made a big difference. Latency went up to 25-95ms.


	Matthias Meixner

Matthias Meixner                       meixner(at)informatik(dot)tu-darmstadt(dot)de
Technische Universit├Ąt Darmstadt
Datenbanken und Verteilte Systeme              Telefon (+49) 6151 16 6232
Wilhelminenstra├če 7, D-64283 Darmstadt, Germany    Fax (+49) 6151 16 6229

In response to


pgsql-performance by date

Next:From: Justin CliftDate: 2003-02-21 09:16:18
Subject: Re: performance issues for processing more then 150000
Previous:From: Shridhar DaithankarDate: 2003-02-21 08:42:25
Subject: Re: performance issues for processing more then 150000 records / day.

Privacy Policy | About PostgreSQL
Copyright © 1996-2017 The PostgreSQL Global Development Group