Hi, > The thing behind the RETURNS in a function is always a data type, > regardless if it is one that has been explicitly declared with > CREATE TYPE or implicitly by CREATE TABLE. > > There are no NOT NULL conditions for data types. > > NOT NULL only exists for table columns. Thanks for the informative reply. As I mentioned in the message to Tom, I think I understand the source of the problem. In SQL, type constraints are not seen as creating different types, whereas in OCaml they do. (I still maintain that OCaml's way of doing things is more correct on a fundamental level, though). > Have you considered an ON SELECT ... DO INSTEAD rule? > http://www.postgresql.org/docs/current/static/rules.html > > You could create a table that represents the query and > define a SELECT rule on it. Thanks, I'll investigate that... Regards, C.S. ____________________________________________________________________________________ Boardwalk for $500? In 2007? Ha! Play Monopoly Here and Now (it's updated for today's economy) at Yahoo! Games. http://get.games.yahoo.com/proddesc?gamekey=monopolyherenow ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend