Re: Simple join doesn't use index

On Tue, Jan 29, 2013 at 8:24 AM, Alex Vinnik <alvinnik(dot)g(at)gmail(dot)com> wrote:

> On Mon, Jan 28, 2013 at 6:55 PM, Filip Rembiałkowski <plk(dot)zuber(at)gmail(dot)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 outdated.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