单项选择题
A. When a successful backup is recorded in the RMAN repository， then a backup of the current control file is performed.
B. When a structural change is made to the database， then a backup of the current control file is performed.
C. When a successful backup is performed in the RMAN repository， then a backup of the spfile is performed.
D. When a structural change is made to the database， then a backup of the alert log file will be performed.
单项选择题 You issued the RMAN> SHOW ALL； command. The output of this command is as follows： After analyzing the output， which conclusion will you draw？（）
多项选择题 You issued the RMAN>SHOW ALL； command. The output of the command is as follows： After analyzing this output， what conclusion can you draw？ （）
单项选择题 You are maintaining the SALES database of a company. You have never backed up the USERS tablespace that is currently offline. On Sunday， you issued the following commands： CONFIGURE DEFAULT DEVICE TYPE TO sbt； CONFIGURE BACKUP OPTIMIZATION ON； CONFIGURE RETENTION POLICY TO REDUNDANCY 3； From Monday to Saturday， you performed the following actions： Day Action Monday BACKUP DATABASE Tuesday BACKUP DATABASE Wednesday BACKUP DATABASE Thursday BACKUP DATABASE Friday BACKUP DATABASE Saturday BACKUP DATABASE How many times will the backup of the USERS tablespace be performed？（）