If one defines a restriction such that 'COLUMN = VALUE' for a specific table, in a theoretical sort of model that completely ignores implementation difficulty, or changes to the restriction, I think it would be safe to not store COLUMN in the tuple. If the tuple is stored, then COLUMN = VALUE, so when fetched, the value will be VALUE.
Back to the real world, this would be difficult to implement without treating the column special from the point of table creation, and preventing the restriction from being altered without re-building the table... :-) Cheers, mark -- [EMAIL PROTECTED] / [EMAIL PROTECTED] / [EMAIL PROTECTED] __________________________ . . _ ._ . . .__ . . ._. .__ . . . .__ | Neighbourhood Coder |\/| |_| |_| |/ |_ |\/| | |_ | |/ |_ | | | | | | \ | \ |__ . | | .|. |__ |__ | \ |__ | Ottawa, Ontario, Canada One ring to rule them all, one ring to find them, one ring to bring them all and in the darkness bind them... http://mark.mielke.cc/ ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org