OCP certified DBA Interview Questions

1. What is the difference between the WHERE clause and the HAVING clause on a SQL statement?

2. What is SQL.BSQ?

3. What is the difference between a static and a dynamic cursor and when would you choose one over the other?

4. Describe the most difficult crash and restore you have ever had to deal with in great and painful detail.

5. What dba_ and v$ objects should be available to developers and why?

6. Go to the whiteboard and demonstrate your knowledge of ALL ASPECTS of the Oracle Security Model.

7. Explain the difference between UNDO and ROLLBACK as implemented inOracle 9i and explain why you would use one rather than the other.

8. what you would do if you received a half-dozen or so common error messages including ORA-00600 and ORA-01555 and make sure you understood multiversioning and other basic architecture matters.

9. A series of questions hardware platform related such as, if a Solaris environment, what is in /etc/system and how does it relate to Oracle.

10. Three users at a time giving the following command:

alter database backup controlfile to trace;

How can you differentiate the file using the filename itself?

11. As a Oracle DBA what are all the UNIX file you should be familar with?

12. When you execute:

alter tablespace begin backup;

How can Oracle engine can identify that the corresponding datafiles are in backupmode?


13. When exporting using filesize parameter I have generated three files. How the oracle name this three files?


14. One of my rollback segments got corrupted? How can I rectified?


15. When yesterday developer gives the following command:

select count(*) from
it gives the output within minutes

Today the same command takes hours? What will u check?


16. When the developer trying to compile the package. But the database gets hanged? What will u check?


17. What is the use of query in Tkprof?


18. What is the maximum number of value allowed in parse column?


19. How can we force the query not to use the index? (Something else then a using a hint)


20. Till yesterday the query is running smoothly. But today the develper is complaining? How will u start your tuning?


21. What is the difference between count(*) and count(1)?