create database test; \c test create table base (foo int not null); create table derived () inherits (base); alter table derived alter foo drop not null; insert into derived values(null); Dump it, and the dump will not include any command to drop the not null constraint on derived.foo, so restore will fail. -- Scott Ribe scott_ribe@xxxxxxxxxxxxxxx http://www.killerbytes.com/ (303) 722-0567 voice