DBMS Objective Questions and Answers

This DBMS quiz contains carefully curated objective questions with correct answers and clear explanations. It is designed for computer science students, backend developers, and interview preparation, focusing on database design, SQL internals, transactions, indexing, and performance tuning.

Practice DBMS MCQs with Detailed Explanations

Answer at least 12 questions to submit.

1

Which normal form eliminates transitive dependency?

Easy
2

Which SQL clause is evaluated first in query execution?

Medium
3

Which index structure is best suited for range queries?

Medium
4

What anomaly is prevented by 2NF?

Medium
5

Which isolation level allows dirty reads?

Medium
6

Which schedule is conflict serializable?

High
7

What is the main purpose of a checkpoint in recovery?

Medium
8

Which join algorithm is most efficient when one relation fits entirely in memory?

Medium
9

Which condition causes a deadlock?

Medium
10

Which operation cannot be performed on a view without INSTEAD OF trigger?

Medium
11

Which locking protocol guarantees conflict serializability?

High
12

Which normal form is stricter than 3NF?

Medium
13

What is the output of COUNT(column) when all values are NULL?

Medium
14

Which index consumes the least storage?

Medium
15

What does WAL ensure?

High