Hi! Thank you everyone for your responses. I investigated them. I have also found composite type operators [1]. There is no way to tell the EXCEPT operator to use *= as its equality operator? *EXCEPT would seem to be a useful operator to have. :-) I am not sure about performance though. EXCEPT is generally fast, but probably because it can use indices, not sure how fast *= is, given that it is comparing binary representations. What is experience with this operator of others? Mitar [1] https://www.postgresql.org/docs/current/functions-comparisons.html#COMPOSITE-TYPE-COMPARISON -- http://mitar.tnode.com/ https://twitter.com/mitar_m