Re: Index Scans become Seq Scans after VACUUM ANALYSE

Indeed - I had a delayed post (sent from the wrong email address) which
mentioned that the cache is obviously at play here. I still find it
amazing that the file system would cache 2gb :) The numbers are
definitely correct though...they are actually the second set.

I'm running a test with a larger file size to remove the cache effects
(having realise that ulimit is the biz). Will post again shortly.

Tom - have you had a change to look at the test prg I wrote? Is it
working as desired?

Cheers,

Mark

On Fri, 2002-04-19 at 00:56, Tom Lane wrote:
> Michael Loftis <mloftis@wgops.com> writes:
> > Somethings wrong with the random numbers from the sun... re-run them, 
> > that first sample is insane....  Caching looks like it's affecctign your 
> > results alot...
> 
> Yeah; it looks like the test case is not large enough to swamp out
> caching effects on the Sun box.  It is on the Linux box, evidently,
> since the 10:1 ratio appears very repeatable.
> 
> 			regards, tom lane
> 
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