Re: Slow 1st queries and RAM size

On Wed, Jan 08, 2014 at 02:23:03PM -0800, Brian Ghidinelli wrote:
>
> Looking at pgfouine, I have slow queries each day, here's one that
> took 7s for which I just ran explain analyze:
>
> QUERY PLAN
> ---------------------------------------------------
> Sort (cost=32920.99..32922.31 rows=530 width=399) (actual
> time=7133.321..7133.423 rows=637 loops=1)
>
> Then, I run it again a min later and I get:
>
> QUERY PLAN
> --------------------------------------------------
> Sort (cost=32920.99..32922.31 rows=530 width=399) (actual
> time=236.774..236.864 rows=637 loops=1)
>
> Is this the data not being in the filesystem cache on the first try
> and it being so on the second?

Yes.

One tool you might use to mitigate this is pgfincore.
https://github.com/klando/pgfincore
http://villemain.org/projects/pgfincore

Cheers,
David.
--
David Fetter <david(at)fetter(dot)org> http://fetter.org/
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