15 commonly asked SQL & PL/SQL Interview Questions in Oracle

1. Difference between TRUNCATE and DELETE?
2. Difference between DECODE and CASE?
3. What is RANK and DENSE RANK?
4. What is cursor and its attributes?
5. What is BULK COLLECT and how does it work?
6. Difference between various Collection Types?
7. What are the various ways to do the Exception Handling in Oracle?
8. Few performance tuning techniques?
9. What is the use of Index, its types and how does indexes help in performance improvement?
10. Describe the Triggers and its types with example?
11. What is View and Materialized view?
12. Describe ref cursor using example?
13. How does queries execute in Oracle? Describe the process of it’s execution?
14. What would you check if the query is running long than expected?
15. What is Mutating Trigger?