Top 50 Most Asked Database Interview Questions

Table of contents#

Questions#

1. What are the differences between SQL and NoSQL databases?#

2. How do you design a database schema for a given application?#

3. What is normalization, and why is it important?#

4. What are indexes, and how do they improve database performance?#

5. What is a primary key, and why is it important?#

6. What are the different types of joins in SQL, and when would you use each?#

7. What are transactions, and why are they important in databases?#

8. How do you handle database migrations?#

9. What are stored procedures, and what are their advantages and disadvantages?#

10. How do you optimize SQL queries for performance?#

11. What is database sharding, and when should it be used?#

12. How do you ensure data consistency across distributed systems?#

13. What are the common causes of database deadlocks, and how do you prevent them?#

14. What are the differences between relational and non-relational databases?#

15. What is the role of a database cache, and how does it work?#

16. How do you manage database security and access control?#

17. What are database replication and its benefits?#

18. What is a database view, and how is it used?#

19. How do you handle database backups and restore operations?#

20. What tools do you use for database monitoring and profiling?#

21. What is a foreign key, and how does it enforce referential integrity?#

22. What is denormalization, and when would you use it?#

23. How do you implement full-text search in a database?#

24. What is the CAP theorem, and how does it relate to distributed databases?#

25. What are the differences between a clustered and a non-clustered index?#

26. What is the difference between DELETE and TRUNCATE commands in SQL?#

27. How do you handle large-scale data imports and exports in a database?#

28. What is a materialized view, and how does it differ from a regular view?#

29. How do you ensure high availability in a database system?#

30. What are the trade-offs between consistency and availability in distributed systems?#

31. How do you design a database for multi-tenant applications?#

32. What is the role of an ORM (Object-Relational Mapping) in database management?#

33. How do you use transactions to ensure data integrity in a concurrent environment?#

34. What is a connection pool, and why is it important for database performance?#

35. What are the benefits and drawbacks of using stored procedures versus application logic?#

36. How do you manage database versions and change control?#

37. What is a database trigger, and how is it used?#

38. How do you handle schema changes in a live production database?#

39. What is eventual consistency, and how does it differ from strong consistency?#

40. How do you implement role-based access control in a database?#

41. What are the considerations for selecting a database technology for a new project?#

42. How do you manage data archiving and purging in a database?#

43. What are the differences between horizontal and vertical scaling in databases?#

44. How do you handle time-series data in a database?#

45. What are the differences between synchronous and asynchronous replication?#

46. How do you implement audit trails and logging in a database?#

47. What are some best practices for database indexing?#

48. How do you use database constraints to enforce data integrity?#

49. What is the role of a database administrator, and how does it differ from a database developer?#

50. How do you assess the performance and scalability of a database system?#