Greetings, > I think I got it : > > ALTER TABLE shelves ADD CONSTRAINT shelves_excl EXCLUDE USING gist( array_remove((ARRAY[l_mug_id,c_mug_id,r_mug_id]::int[]),NULL) WITH && ); > > but the caveat is I had to cast to 32-bit int array. Haven't found any opclass for int8 (bigint) in intarray extension. I tried this and got the opclass error for the int8 and (since postgres is so wonderfully extensible) considered trying to write the oppclass for bigint. But ultimately writing the trigger as suggested by Laurenz is much easier. So that is the route I went, Thanks all for your input. Rhys Peace & Love | Live Long & Prosper
