Re: Plan invalidation design

From: Lukas Kahwe Smith <smith(at)pooteeweet(dot)org>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Subject: Re: Plan invalidation design
Date: 2007-02-18 10:07:24
Message-ID: 45D8255C.3030706@pooteeweet.org
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Tom Lane wrote:
> Lukas Kahwe Smith <smith(at)pooteeweet(dot)org> writes:
>> I remember that there was discussion about invalidating plans who's
>> estimated cost turn out to be severely off when executed.
>
> That's something we might think about after the infrastructure is in
> place. But the question to answer is why the re-plan won't yield
> just the same plan as before.

Yeah, also invalidating plans like this only really makes sense once we
have the ability to keep multiple plans around for different sets of
parameters. Otherwise we could also end up in a situation where after
every execution we determine that a re-plan is necessary because the
parameters used differ in distribution.

regards,
Lukas

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