Backup & Recovery Questions for an Oracle DBA

Some of the Common Backup and Recovery Interview Questions for Oracle Database Administrator.  These questions are common for both Senior Oracle DBA or Junior DBA. I have compiled these questions based upon the feedback I got from many candidates who have attended interviews in various MNC's

1. Which types of backups you can take in Oracle?

2. A database is running in NOARCHIVELOG mode then which type of backups you can take?

3. Can you take partial backups if the Database is running in NOARCHIVELOG mode?

4. Can you take Online Backups if the the database is running in NOARCHIVELOG mode?

5. How do you bring the database in ARCHIVELOG mode from NOARCHIVELOG mode?

6. You cannot shutdown the database for even some minutes, then in which mode you should run
the database?

7. Where should you place Archive logfiles, in the same disk where DB is or another disk?

8. Can you take online backup of a Control file if yes, how?

9. What is a Logical Backup?

10. Should you take the backup of Logfiles if the database is running in ARCHIVELOG mode?

11. Why do you take tablespaces in Backup mode?

12. What is the advantage of RMAN utility?

13. How RMAN improves backup time?

14. Can you take Offline backups using RMAN?

15. How do you see information about backups in RMAN?

16. What is a Recovery Catalog?

17. Should you place Recovery Catalog in the Same DB?

18. Can you use RMAN without Recovery catalog?

19. Can you take Image Backups using RMAN?

20. Can you use Backupsets created by RMAN with any other utility?

21. Where RMAN keeps information of backups if you are using RMAN without Catalog?

22. You have taken a manual backup of a datafile using o/s. How RMAN will know about it?

23. You want to retain only last 3 backups of datafiles. How do you go for it in RMAN?

24. Which is more efficient Incremental Backups using RMAN or Incremental Export?

25. Can you start and shutdown DB using RMAN?

26. How do you recover from the loss of datafile if the DB is running in NOARCHIVELOG mode?

27. You loss one datafile and it does not contain important objects. The important objects are there in other datafiles which are intact. How do you proceed in this situation?

28. You lost some datafiles and you don't have any full backup and the database was running in NOARCHIVELOG mode. What you can do now?

29. How do you recover from the loss of datafile if the DB is running in ARCHIVELOG mode?

30. You loss one datafile and DB is running in ARCHIVELOG mode. You have full database backup of 1 week old and partial backup of this datafile which is just 1 day old. From which backup should you restore this file?

31. You loss controlfile how do you recover from this?

32. The current logfile gets damaged. What you can do now?

33. What is a Complete Recovery?

34. What is Cancel Based, Time based and Change Based Recovery?

35. Some user has accidentally dropped one table and you realize this after two days. Can you recover this table if the DB is running in ARCHIVELOG mode?

36. Do you have to restore Datafiles manually from backups if you are doing recovery using RMAN?

37. A database is running in ARCHIVELOG mode since last one month. A datafile is added to the database last week. Many objects are created in this datafile. After one week this datafile gets damaged before you can take any backup. Now can you recover this datafile when you don't have any backups?

38. How do you recover from the loss of a controlfile if you have backup of controlfile?

39. Only some blocks are damaged in a datafile. Can you just recover these blocks if you are using RMAN?

40. Some datafiles were there on a secondary disk and that disk has become damaged and it will take some days to get a new disk. How will you recover from this situation?

41. Have you faced any emergency situation. Tell us how you resolved it?

42. At one time you lost parameter file accidentally and you don't have any backup. How you will recreate a new parameter file with the parameters set to previous values.

Also See Oracle DBA Techincal Questions and UNIX Questions Asked to a Oracle DBA