Re: R: R: slow seqscan after vacuum analize

On Thu, 05 Feb 2004 14:33:45 -0500, Tom Lane wrote
> "Edoardo Ceccarelli" <eddy@axa.it> writes:
> > Given a query that HAS to be executed with a seqscan I have noticed an
> > increase in time comparing before and after the vacuum.
>
> This is really hard to believe --- I cannot think of any mechanism that
> would result in that effect.  Unless the vacuum were flushing the
> kernel's disk cache, but the effects of that would only persist for one
> scan.  You did say that the increased time is repeatable if you do
> multiple seqscans after the vacuum?
>
>             regards, tom lane


Yes, I can assure you that was repeatable and has disappeared only after a
VACUUM FULL ANALYZE

it was something really stable in it's bad behaviour. I am going to make some
test soon and I will post here the results.

Best Regards
Edoardo

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