Re: Simple join doesn't use index - Mailing list pgsql-performance

From Filip Rembiałkowski
Subject Re: Simple join doesn't use index
Date
Msg-id CAP_rwwmwjZh+UX2cFztR3wKeEQqnXW=kNx_XhrN2E76K5bxduA@mail.gmail.com
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In response to Re: Simple join doesn't use index  (Alex Vinnik <alvinnik.g@gmail.com>)
Responses Re: Simple join doesn't use index
List pgsql-performance
On Tue, Jan 29, 2013 at 8:24 AM, Alex Vinnik <alvinnik.g@gmail.com> wrote:
On Mon, Jan 28, 2013 at 6:55 PM, Filip Rembiałkowski <plk.zuber@gmail.com> wrote:

do you know pgtune?
it's a good tool for starters, if you want a fast postgres and don't really want to learn what's behind the scenes.
Yeah.. I came across pgtune but noticed that latest version dated 2009-10-29 http://pgfoundry.org/frs/?group_id=1000416 which is kind of outdated. Tar file has settings for pg 8.3. Is still relevant?

Yes, I'm sure it will not do anything bad to your config.
 

random_page_cost=1 might be not what you really want.
it would mean that random reads are as fast as as sequential reads, which probably is true only for SSD
What randon_page_cost would be more appropriate for EC2 EBS Provisioned volume that can handle 2,000 IOPS? 


I'd say: don't guess. Measure.
Use any tool that can test sequential disk block reads versus random disk block reads.
bonnie++ is quite popular.



Filip



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