Which of the following is a true statement about indexes? MCQ with Answer and Explanation

Question

Share Report Error

Which of the following is a true statement about indexes?

A. Indexes cannot be created on views

B. Indexes are only used for primary keys

C. Indexes improve the speed of SELECT queries but can slow down INSERT, UPDATE, and DELETE operations

D. Indexes always improve performance

Answer: Option C

Solution (By JKSSB Mock Tests)

Indexes speed up data retrieval but require additional maintenance during data modifications, which can slow down DML operations.

This question belongs to: Computer Database Management System (DBMS)

Request complete Subject PDF

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Database Management System (DBMS) Questions

Question #1

Share Report

Which SQL command is used to permanently remove an entire table structure along with all its data from the database?

A. TRUNCATE

B. DROP

C. DELETE

D. REMOVE

View Answer & Solution Discuss

Get Complete Subject PDF for Computer

Correct Answer: Option B

Explanation:
The DROP command is a DDL statement that completely removes a table's structure, definition, and all its associated data from the database.

This question belongs to: Computer Database Management System (DBMS)

Question #2

Share Report

What is the purpose of the SQL 'JOIN' clause?

A. To combine columns from multiple tables into a single table

B. To delete records from a table

C. To combine rows from two or more tables based on a related column

D. To create a new table

View Answer & Solution Discuss

Get Complete Subject PDF for Computer

Correct Answer: Option C

Explanation:
JOIN is used to combine rows from different tables based on a common column, allowing querying across related tables.

This question belongs to: Computer Database Management System (DBMS)

Question #3

Share Report

Which of the following is a valid SQL constraint that ensures a column's values are all distinct?

A. Both A and B

B. PRIMARY KEY

C. DISTINCT

D. UNIQUE

View Answer & Solution Discuss

Get Complete Subject PDF for Computer

Correct Answer: Option A

Explanation:
Both UNIQUE and PRIMARY KEY enforce uniqueness. PRIMARY KEY also implies NOT NULL.

This question belongs to: Computer Database Management System (DBMS)

Explore All Database Management System (DBMS) MCQs