A subtype inherits its primary key from its supertype. If the supertype is Party for example, we copy the Party Id down into the primary keys of the subtypes Person and Organization:
Sometimes we rename the subtype primary keys, but it is still the primary key from the supertype. For example, we can rename Party Id in the primary key of Person to Person Id, yet it is still the Party Id.
Can a subtype ever have a different primary key than its supertype?