On 19 Mar 2003, James Gregory wrote:
> I hope this one is just some misunderstanding on my part.
Referential integrity constraints currently apply only to the explicitly
named table. In addition, the saleable_item primary key on id is not
inherited by product (and so there can be duplicates in product - even if
you put a unique constraint on product(id), you still can have duplicates
between saleable_item and product).