Top 20 DBMS Questions

  1. What is a Database Management System (DBMS)?

    • Explain the purpose and functions of a DBMS.

    • Differences between DBMS and RDBMS.

  2. What are the different types of DBMS?

    • Hierarchical, Network, Relational, and Object-oriented DBMS.
  3. Explain ACID properties in a DBMS.

    • Atomicity, Consistency, Isolation, Durability.
  4. What is normalization? Explain its types.

    • 1NF, 2NF, 3NF, BCNF, and higher normal forms.
  5. What are joins in SQL? Explain different types.

    • Inner Join, Left Join, Right Join, Full Join, Cross Join.
  6. What is a primary key?

    • Definition and importance of primary keys in a database.
  7. What is a foreign key?

    • Definition and role of foreign keys in maintaining referential integrity.
  8. What is indexing? How does it improve query performance?

    • Types of indexes: B-Tree, Hash, Bitmap, etc.
  9. Explain the difference between DELETE, TRUNCATE, and DROP commands.

    • Use cases and performance implications of each command.
  10. What is a transaction?

    • Definition, lifecycle, and importance in DBMS.
  11. What is a deadlock? How can it be resolved?

    • Causes of deadlocks and techniques for deadlock prevention and resolution.
  12. What is SQL injection? How can it be prevented?

    • Explanation of SQL injection attacks and best practices for prevention.
  13. Explain the concept of views in SQL.

    • Use cases and benefits of using views.
  14. What are stored procedures and functions?

    • Differences, advantages, and use cases.
  15. What is a trigger in SQL?

    • Definition, types, and examples of triggers.
  16. Explain the difference between clustered and non-clustered indexes.

    • Use cases and performance considerations.
  17. What are the different isolation levels in a DBMS?

    • Read Uncommitted, Read Committed, Repeatable Read, Serializable.
  18. What is the difference between OLTP and OLAP?

    • Characteristics and use cases of Online Transaction Processing (OLTP) and Online Analytical Processing (OLAP).
  19. Explain the concept of a database schema.

    • Definition and types of database schemas: physical and logical.
  20. What is the purpose of the GROUP BY and HAVING clauses in SQL?

    • Use cases and examples of GROUP BY and HAVING clauses.