Hello, I've got the following situation: select expensive_function(table) from table where expensive_function(table) is not null; Is there a way to avoid that expensive_function is evaluated twice (if it's not null) ? I've tried stuff like immutable, but that doesn't do anything for me. Of course I can do a select into, but my guess is it would be even more expensive than evaluating these functions twice. Thanks in advance, Han Holl ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings