Your database is up and running and one of your three control files is accidentally erased.
You start RMAN and run the following command:
RESTORE CONTROLFILE FROM AUTOBACKUP;
Which of the following statements is true? (Choose all that apply.)
A.
The command restores only the missing control file.
B.
The command restores all the control files.
C.
The command fails because the database is running.
D.
This is the correct way to address this problem.
E.
This is not the correct way to address this problem.
Explanation:
During the database running, the control files are locked by the database instance, you must
shutdown the database and startup at NOMOUNT status to restore a missing control file.
And you have to open database with RESETLOGS option, due to control file change.
C and E is correct
For C:
https://docs.oracle.com/cd/B19306_01/backup.102/b14192/recov004.htm
6.4.1.2 Restore of the Control File from Control File Autobackup
If you are not using a recovery catalog, you must restore your control file from an autobackup. If you want to restore the control file from autobackup, the database must be in a NOMOUNT state. You must first set the DBID for your database, and then use the RESTORE CONTROLFILE FROM AUTOBACKUP command:
RMAN> SET DBID 320066378;
RMAN> RUN {
SET CONTROLFILE AUTOBACKUP FORMAT
FOR DEVICE TYPE DISK TO ‘autobackup_format’;
RESTORE CONTROLFILE FROM AUTOBACKUP;
}
RMAN uses the autobackup format and DBID to determine where to hunt for the control file autobackup. If one is found, RMAN restores the control file from that backup to all of the control file locations listed in the CONTROL_FILES initialization parameter.
For E:
https://docs.oracle.com/cd/B19306_01/backup.102/b14192/recov004.htm
6.4.1 Restoring the Control File from Backup
Loss or corruption of all copies of your control file requires restore of the control file from backup. The RESTORE CONTROLFILE command is used to restore the control file.
Note:
After restoring the control files of your database from backup, you must perform complete media recovery of the database as described in “Performing Media Recovery of a Restored Database, Tablespace or Datafile”, and then open your database with the RESETLOGS option. The only exception is the case described in “Restore of the Control File to a New Location”, where you restore your control file to a location not listed in the CONTROL_FILES initialization parameter. In that case, you create a copy of your control file in the specified location without touching your running database.
RMAN can restore the control file to its default location (determined by rules described in the following section) or to one or more different locations of your choice, using the RESTORE CONTROLFILE…