Which of the following statements about indexes is incorrect?
A) An index is a database object that stores a frequently referenced value and the row id (ROWID) of the record containing that value.
B) An index is only beneficial if a large percentage of a table is expected to be returned in query results.
C) An index is used to speed up the process of searching for specific data.
D) An index is updated automatically every time a DML operation is performed on the underlying table, which can slow down execution of the DML operation.

Question

Quizplus · Accepted Answer

This statement is incorrect because an index is beneficial even if a small percentage of a table is expected to be returned in query results. In fact, indexes can be very useful for improving query performance even if only a small subset of data is being retrieved.

Which of the Following Statements About Indexes Is Incorrect