RMAN interview questions

Heman Sahi

1. Your RMAN backup triggered, you deleted snapshot controlfile at backend, what will happen to your running backup ?
2. what happens internally when we issue ‘ RESYNC CATELOG’ for recovery catelog ?
3. You enabled Block change tracking and then immediately performed level 1 backup, will BCT be used ?
4. Your RMAN backup triggered, you added one more datafile during the backup. Will RMAN take backup of that ?
5. What is SYSBACKUP privilege, does it require passwordfile authentication or OS authentication ?

As user SYSBACKUP with the SYSBACKUP privilege. SQL*Plus prompts for the SYSBACKUP user password.
When connecting as user SYSBACKUP, you must connect AS SYSBACKUP.
It uses password file authentication.

6. We can use MULTISECTION with RMAN backupsets. Can we use MULTISECITON backup with image copies?

Oracle Database 12c New Feature enhances the multi section backup, introduced in 11g: You can use it now for image copies also!

Active RMAN duplicate clone 12c using section size and compress backupset

7. You took a backup with password-based encryption (SET ENCRYTION ON IDENTIFIED BY) and then lost the password, now how to decrypt it ?

Skant Gupta

8.I have a image copy of database, can we apply level 1 incremental backup on that and recover the database?

9.If you are the DBA, will you choose differential or cumulative and why?

Differential will take incremental backup in a daily fashion where as cumulative will take backup so that it includes all the other day changes also.

10.How many recovery catalogs you will create for 100 prod databases?

Only one is enough.

11.If we don’t use recovery catalog, where the backup information is stored and till how many days?

It will be stored in controlfiles and number of days are dependent on CONTROLFILE_RECORD_KEEP_TIME parameter. Generally it is 7 days.

12.Suppose we lost datafiles in recovery catalog, how to recover them?

As recovery catalog is also a database, we will be performing backup for the same. So we can restore and recover from that backup.

13.What are the new features of Oracle 10g,11g,12c RMAN?


14.Why is it not correct to use OS level housekeeping of archive logs when RMAN does the housekeeping?


15.If we are adding a datafile in between RMAN backup will that be backed up or not ? If Yes How and if not why ?

16.How to check the RMAN backup status and timings?

SQL> col STATUS format a9
SQL> col hrs format 999.99
to_char(START_TIME,’mm/dd/yy hh24:mi’) start_time,
to_char(END_TIME,’mm/dd/yy hh24:mi’) end_time,
elapsed_seconds/3600 hrs from V$RMAN_BACKUP_JOB_DETAILS
order by session_key;


17.User fire delete noorompt backup; but backup should not get deleted ..how will achieve this?

18.Why rman create snapshot controlfile..and what is snapshot controlfile


19.From where does the list and report command get the input

Both the commands command quering v$ and recovery catalog views. V$BACKUP_FILES or many of the recovery catalog views such asRC_DATAFILE_COPY or RC_ARCHIVED_LOG.

20.Does oracle ask before dropping a catalog? If yes how many times

The default is two times one for the actual command, the other for confirmation


21.What are the advantages of rman backup over user managed backup ?
22.Which stage a database shall be in when rman cold backup is performed ?
23.What are the different types of incomplete recovery one can perform using rman ?
24.How can the backup performance be tuned in rman ?
25.What is the difference between delete obsolete and delete expired ?

26.Suppose your archive log directory is filling up fast and the rman backup is not running due to some tape issue and in order to get some breathing space you have decided to move some archive logs to a different filesystem. Now at the time of your next backup what are the steps you have to perform so that the backup picks up those archive logs which were moved ?

27.What are the rman commands to detect one or more corrupt block and how to recover those ?

28.What is the command to include control file with each rman backup ?

If we want to create a backup of control files each time we do a backup of the database, use the include current control file command.

29.What is incarnation based recovery and how is it performed in rman ?

30.What is the difference between rman incremental backup and rman full backup ?


31.If you upgraded or applied PSU on your database?Do you need to do any thing in catalog?

32.Which memory area used during RMAN backup?

33.How you improve performance for bigfile tablespace backup?

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