On Wed, 23 Jan 2002 pgsql-bugs@postgresql.org wrote:
> Short Description
> Primary key not working correctly with inheritance
This is a well known deficiency with the inheritance system. Certain
things (primary and foreign keys as an example) don't inherit right now.
For primary key, AFAIK we don't have a real mechanism in place to do
a single primary key over multiple tables, but if you just want child
to be unique across itself (ie, you could insert a 1 in parent and in
child, but not two 1's in child) you can make a unique index across
child(id).