Database Management Systems MCQ
Test your DBMS knowledge with 100 multiple choice questions covering fundamentals to advanced concepts, with instant feedback and explanations.
What is a database?
2What is a primary key?
3What is a foreign key?
4What does SQL stand for?
5What does SELECT * FROM users do?
6What is normalization?
7What is the difference between DDL and DML?
8What is a JOIN in SQL?
9What is the difference between INNER JOIN and LEFT JOIN?
10What is an index in a database?
11What is ACID in databases?
12What is a transaction?
13What is a stored procedure?
14What is a view in SQL?
15What does GROUP BY do in SQL?
16What is the difference between WHERE and HAVING?
17What is the purpose of ORDER BY?
18What is a NULL value in SQL?
19What is the difference between CHAR and VARCHAR?
20What is a database schema?
21What is denormalization?
22What is a composite key?
23What does DISTINCT do in SQL?
24What is a trigger in databases?
25What is the difference between TRUNCATE and DELETE?
26What is a relational database?
27What is the difference between a clustered and non-clustered index?
28What is a subquery?
29What is database replication?
30What is the LIMIT clause in SQL?
31What is a database cursor?
32What is the difference between a relation and a table?
33What is a database transaction log?
34What is a self-join?
35What is an ERD (Entity-Relationship Diagram)?
36What are aggregate functions in SQL?
37What is OLTP vs OLAP?
38What is a unique constraint?
39What is the BETWEEN operator in SQL?
40What is a NoSQL database?
What is the first normal form (1NF)?
2What is the third normal form (3NF)?
3What is a transaction isolation level?
4What is a dirty read in database transactions?
5What is the difference between optimistic and pessimistic locking?
6What is a B-tree index?
7What is a hash index?
8What is sharding in databases?
9What is database partitioning?
10What is the difference between correlated and uncorrelated subqueries?
11What is the CAP theorem's relevance to distributed databases?
12What is a materialized view?
13What is query optimization?
14What is the purpose of database statistics?
15What is a deadlock in a database context?
16What is MVCC (Multi-Version Concurrency Control)?
17What is a cursor in database programming?
18What is database connection pooling?
19What is a covering index?
20What is the difference between SQL and NoSQL databases for scalability?
21What is a foreign key constraint and cascading?
22What is data warehousing?
23What is the difference between star schema and snowflake schema?
24What is a window function in SQL?
25What is the difference between UNION and UNION ALL?
26What is a database trigger and when should it be avoided?
27What is columnar storage and why is it used in analytical databases?
28What is the second normal form (2NF)?
29What does the EXPLAIN command show in most relational databases?
30What is a non-repeatable read?
31What is a phantom read?
32What is the purpose of the EXISTS operator in SQL?
33What is referential integrity?
34What is an anti-join in SQL?
35What is the purpose of the EXPLAIN ANALYZE command compared to plain EXPLAIN?
36What is a surrogate key?
37What is the purpose of the GRANT and REVOKE statements in SQL?
38What is query result caching and what risk does it introduce?
39What is the difference between a natural join and an inner join with an explicit ON clause?
40What is the purpose of the COALESCE function in SQL?
What is the difference between 2PL (Two-Phase Locking) and MVCC?
2What is the Aries recovery algorithm?
3What is lock escalation in databases?
4What is the difference between read committed and repeatable read isolation levels?
5What is a query execution plan and how do you analyze it?
6What is database connection pooling vs. connection multiplexing?
7What is the difference between synchronous and asynchronous replication?
8What is a LSM-tree and which databases use it?
9What is write amplification in database storage engines?
10What is the Saga pattern in distributed transactions?
11What is the difference between PostgreSQL's MVCC and MySQL InnoDB's MVCC?
12What is write-ahead logging (WAL) and why is it fundamental to database recovery?
13What is temporal data management in databases?
14What is the difference between row-level security and view-based security?
15What is the Google Spanner database and its significance?
16What is HTAP (Hybrid Transactional/Analytical Processing)?
17In the context of distributed transactions, what problem does the Two-Phase Commit (2PC) protocol solve, and what is its main weakness?
18How does cost-based query optimization decide between a nested loop join and a hash join?
19What is the "thundering herd" problem in the context of database connection and cache management, and how is it typically mitigated?
20What is "snapshot isolation" and how can it still permit write skew anomalies?