What is an Index? Explain how to create an Index.

Correct Answer: An index is a object which is used to improve performance during retrieval of records CREATE [UNIQUE] INDEX index_name ON employee[emp_id, emp_name,dept_id] [COMPUTE STATISTICS] The UNIQUE keyword is used when combined values of the index should be unique The COMPUTE STATISTICS during the creation of index optimizes the plan of execution of the SQL statement and improves performance