I've been told that not all features of inheritance are implemented. What
this means in practice is that you often have to redeclare constraints on
inherited tables. So in your example you'd need to alter table persons and
add the constraint, but even then I think it might be possible to insert an
objects row and a person row with the same id.
--
Scott Ribe
scott_ribe(at)killerbytes(dot)com
http://www.killerbytes.com/
(303) 665-7007 voice