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

Neat trick

From: Mladen Gogala <mgogala(at)vmsinfo(dot)com>
To: "pgsql-novice(at)postgresql(dot)org" <pgsql-novice(at)postgresql(dot)org>
Subject: Neat trick
Date: 2010-09-14 21:30:28
Message-ID: 4C8FE974.9000801@vmsinfo.com (view raw or flat)
Thread:
Lists: pgsql-novice
I figured out how to speed up the sequential scans using "blockdev" 
command. Essentially, this increases the read-ahead on the underlying 
block device for the file system. It will change the read-ahead value 
for the entire disk, even if there are several partitions on the disk.  
The results are very promising. Unfortunately, I didn't take baseline 
numbers and measure the effect with precision, but the look of it is 
that things are much faster with the read-ahead set to 2048 instead of 
the default 256. The read-ahead is measured in sectors read ahead by the 
OS. The OS is Red Hat Linux, EL 5.5.

-- 
 
Mladen Gogala 
Sr. Oracle DBA
1500 Broadway
New York, NY 10036
(212) 329-5251
http://www.vmsinfo.com 
The Leader in Integrated Media Intelligence Solutions




Responses

pgsql-novice by date

Next:From: Josh KupershmidtDate: 2010-09-14 22:04:30
Subject: Re: transaction is read-only error
Previous:From: Salil WadnerkarDate: 2010-09-14 09:31:43
Subject: transaction is read-only error

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