Re: Scaling further up - Mailing list pgsql-performance

From Paul Thomas
Subject Re: Scaling further up
Date
Msg-id 20040303085718.A24535@bacon
Whole thread Raw
In response to Re: Scaling further up  (johnnnnnn <john@phaedrusdeinus.org>)
Responses Re: Scaling further up
List pgsql-performance
On 02/03/2004 23:25 johnnnnnn wrote:
> [snip]
> random_page_cost should be set with the following things taken into
> account:
>   - seek speed

Which is not exactly the same thing as spindle speed as it's a combination
of spindle speed and track-to-track speed. I think you'll find that a 15K
rpm disk, whilst it will probably have a lower seek time than a 10K rpm
disk, won't have a proportionately (i.e., 2/3rds) lower seek time.

>   - likelihood of page to be cached in memory by the kernel

That's effective cache size.


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