This document contains 40 interview questions related to Oracle PL/SQL development. The questions cover a range of topics including previous project experience, technical challenges, software development lifecycles, database objects like views and materialized views, SQL statements like truncate and delete, PL/SQL structures like procedures, functions and packages, built-in Oracle packages, triggers, query performance tuning, exceptions, cursors, data dictionary tables, arrays and indexes.

1. ORACLE INTERVIEW QUESTIONS
1. Can you tell us something about your previous project? We are more interested to know what technical
PL/SQL programming work you have done in your last project.
2. Can you highlight or describe any technical challenge you have faced and resolved in any of your projects for
which you felt proud of? Please explain the challenge, your approach and the resolution in technical terms.
3. Have you ever been involved in entire life cycle of changes/requests/enhancements/development work or
only in coding (converting Pseudo code/design to PL/SQL programs)? How do you convert any requirement to
design? What are the steps you perform?
4. Difference between VIEW & MATERIALISED VIEW (MV). How do you refresh a MTERIALISED VIEW?
5. Why to use a MV instead of a view? What are the advantages?
6. Difference between truncate and delete.
7. Difference between PL/SQL procedures, functions and packages.
8. Can a PL/SQL function return multiple values?
9. What is inout nocopy parameter?
10. Why would you use a package instead of standalone procedures?
11. What are the ORACLE Inbuilt Packages you are aware of what are their uses?

2. 12. What is the use of DBMS_SQL inbuilt package?
13. Have you written any triggers? Why/When do we use triggers? What are the different types of triggers?
14. What is a mutating trigger?
15. Can we use commit/Rollback inside a trigger? When and how to use it?
16. How to troubleshoot performance issues? For eg: One procedure which normally used to take 5-10 seconds
on an average to get executed has started taking 15 Mins now. What approach you will follow or what are the
steps you will execute to identify the root cause. What can be the probable root causes and what can be done
to fix those causes.
17. How would you tune the SQL?
18. What is complex transformation? Have you used any to generate any report?
19. Difference between type and rowtype?
20. What is a bind variable and where we use it?
21. What is a nested subquery? When and how to create it?
22. What are the aggregate functions you have used or you are aware of?
23. Why we get no data found exception error?

3. 24. Why to go for Create or Replace Procedure option instead of dropping the procedure and then creating the
new one?
25. What is TKPROF and when to use it?
26. What would you add to a query to avoid getting duplicate results ?
27. Describe – UNION, UNION ALL, INTERSECT functionalities.
28. What is SQL on the fly? How to generate and execute it?
29. How do you handle Exceptions?
30. Difference between count(*) and count(1).
31. Have you used OOPS concept in PL/SQL programming?
32. What is ‘SNAPSHOT TOO OLD’ error mean? Why would you get it?
33. What is ‘CONNECT BY PRIOR’ and where we use it?
34. What are Rank and Dense Rank functions?
35. How many types of cursors are there?

4. 36. Have you used any data dictionary tables of ORACLE? Please name some of them and provide a scenario
where you have used those.
37. What are the uses of VARRY and PL/SQL Tables and how to use those.
38. What are the different types of Indexes and how to use those? What is a IOT (Index Organised Table)
39. Have you ever used the MERGE statement?
40. How to execute Bulk Insert/Update? What is UPSERT?