Stephan Szabo <[EMAIL PROTECTED]> writes: > On Fri, 25 Mar 2005, Simon Riggs wrote: >> Could it be that because PostgreSQL has a very highly developed sense of >> datatype comparison that we might be taking this to extremes? Would any >> other RDBMS consider two different datatypes to be comparable?
> We do have a broader comparable than the spec. However, the set of comparisons that we can presently support *with indexes* is narrower than the spec, so rejecting nonindexable cases would be a problem. It's worth noting also that the test being discussed checks whether the PK index is usable for testing the RI constraint. In the problem that started this thread, the difficulty is lack of a usable index on the FK column, not the PK (because that's the table that has to be searched to do a delete in the PK table). We cannot enforce that there be a usable index on the FK column (since indexes on the FK table may not have been built yet when the constraint is declared), and shouldn't anyway because there are reasonable usage patterns where you don't need one. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])