Re: Plan invalidation design - Mailing list pgsql-hackers

From Lukas Kahwe Smith
Subject Re: Plan invalidation design
Date
Msg-id 45D8255C.3030706@pooteeweet.org
Whole thread Raw
In response to Re: Plan invalidation design  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane wrote:
> Lukas Kahwe Smith <smith@pooteeweet.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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