In addition to providing faster access to data,certain indexes also have a second purpose: enforcing a PRIMARY KEY constraint or ____ constraint.
A) FOREIGN KEY
B) CHECK
C) NOT NULL
D) UNIQUE

Question

Quizplus · Accepted Answer

Indexes with a UNIQUE constraint enforce uniqueness of values in a column or a group of columns, which is the purpose of a PRIMARY KEY constraint. Therefore, D is the correct answer. FOREIGN KEY constraint is not related to indexes, CHECK constraint ensures that a column value meets a specified condition, and NOT NULL constraint ensures that a column cannot have a NULL value.

In Addition to Providing Faster Access to Data,certain Indexes Also