"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
