Thread: One-time plans
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Old 04-12-2008, 09:06 AM
Tom Lane
 
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Default Re: One-time plans

"Simon Riggs" <simon@2ndquadrant.com> writes:
> ISTM we've just invented the concept of one-time plans to allow CREATE
> INDEX to work effectively with HOT.


> I'd like to extend that thought back over towards constraint exclusion.
> Currently we don't allow STABLE functions to be used for constraint
> exclusion because that mean plans were valid only if they are
> immediately executed.


> It seems like a very small act to force the plan to be one-time only
> when we have successfully used a STABLE function to exclude a table.


No. STABLE functions are not stable enough for that --- you'd have to
assume they are unchanging across the whole transaction.

regards, tom lane

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