Question

Which statements are correct regarding indexes?

(a) When a table is dropped, the corresponding indexes are automatically dropped

(b) For each DML operation performed, the corresponding indexes are automatically updated

(c) A non-deferrable PRIMARY KEY or UNIQUE KEY constraint in a table automatically creates a unique index

(d) All of the mentioned

I had been asked this question during an online interview.

Question is from Insertion Deletion Predicate Reads topic in section Concurrency Control of Database Management

Answer 1

Correct answer is (d) All of the mentioned

Best explanation: Indexes are used to access the data efficiently.