The values of the primary key of a relation ____.
A) cannot be unique
B) may be unique or non-unique
C) must be unique
D) must consist of a single attribute
E) None of the above.

Question

Quizplus · Accepted Answer

The primary key of a relation must be unique, as it is used to identify each tuple (row) in the relation. A primary key can consist of a single attribute or a combination of attributes. Therefore, option A and D are incorrect. Option B is partially correct, as a primary key may consist of non-unique attributes, but the combination of attributes must be unique. Option E is incorrect as well, as one of the given choices must be correct.

The Values of the Primary Key of a Relation ____