In A Supertype/Subtype Hierarchy, Each Subtype Has:
In A Supertype/Subtype Hierarchy, Each Subtype Has:. We will consider only supertype and subtype hierarchies. Each subtype also inherits the primary key of the supertype.
An attribute of the supertype that determines the target subtype (s) is called the: An attribute of a supertype whose values determine the target subtype or subtypes. Each subtype also inherits the primary key of the supertype.