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.
-- Simon Riggs EnterpriseDB http://www.enterprisedb.com