1: The foreign key depends on the function so the function cannot be dropped first absent CASCADE2: If the function is redefined, one would have to check all rows to verify that they meet the new function's requirements. This could pose a performance issue with DDL.There are obvious workarounds. One could use a trigger and a foreign key.But my questions are:1. Is there enough use in something like this to even try to tackle it?2. Are there any other major showstoppers I haven't thought of?
Purely from a user perspective IMO it seems like a good idea and a logical progression from index expressions. You could even make use of the equivalent index _expression_ if it existed, or (better) insist on it, because the calculated value would have to be UNIQUE anyway (otherwise you end up in all sorts of trouble).
Geoff
