Which of the following is not true about representing subtypes in a relational database design?
A)One table is created for the supertype and one for each subtype.
B)All of the attributes of the supertype are added to the subtype relations.
C)The key of the supertype is made the key of the subtypes.
D)An instance of the supertype may be related to one instance each of several subtypes.

Question

Quizplus · Accepted Answer

All of the attributes of the supertype should not be added to the subtype relations. Only the attributes that are common to all subtypes should be added to the supertype table, while the unique attributes of each subtype should be added to their respective tables.

Which of the Following Is Not True About Representing Subtypes