604.You realize that the control file is damaged in your production database. After restoring the control file
from autobackup, what is the next step that you must do to proceed with the database recovery?
A. Mount the database
B. Open the database in NORMAL mode
C. Open the database in RESTRICTED mode
D. Open the database with the RESETLOGS option
Answer: A
答案解析：
参考control文件恢复实验：http://blog.csdn.net/rlhua/article/details/12625067
Restoring the Control File from the Autobackup
Restoring the control file from an autobackup is similar to the steps you use to restore an SPFILE from an autobackup.
RMAN> startup nomount;
RMAN> restore controlfile from autobackup;
RMAN> alter database mount;
RMAN> recover database;
RMAN> alter database open resetlogs;
Note that since there is no control file, you have to open the database with NOMOUNT and then restore the control file. After you mount the database, you must recover the database, because the backup control file contains information about an older version of the database. For the same reason, you must open the database with RESETLOGS.
RMAN restores the control file to all locations specified by the initialization parameter CONTROL_FILES. If one or more of those locations are still not available, you will have to edit the CONTROL_FILES parameter to specify alternative locations or temporarily restore the control file to a different location:
RMAN> restore controlfile to '/u06/oradata/rest_cf.dbf' from autobackup;