Wow, range types with non-overlapping constraints: http://www.postgresql.org/docs/devel/static/rangetypes.html http://www.postgresql.org/docs/devel/static/rang

Wow, range types with non-overlapping constraints: http://www.postgresql.org/docs/devel/static/rangetypes.html http://www.postgresql.org/docs/devel/static/rangetypes.html CREATE TABLE room_reservation ( room TEXT, during TSRANGE, EXCLUDE USING gist (room WITH =, during WITH &&) ); INSERT INTO room_reservation VALUES ('123A', '[2010-01-01 14:00, 2010-01-01 15:00)'); INSERT INTO room_reservation VALUES ('123A', '[2010-01-01 14:30, 2010-01-01 15:30)'); ERROR: conflicting key value violates exclusion constraint "room_reservation_room_during_excl" DETAIL: Key (room, during)=(123A, [ 2010-01-01 14:30:00, 2010-01-01 15:30:00 )) conflicts with existing key (room, during)=(123A, [ 2010-01-01 14:00:00, 2010-01-01 15:00:00 )). Used to have to rely on the application to do these sorts of constraints.