What information does the report schema command not provide？（） 

单项选择题Whywouldyouexecutethereportobsoletecommand？（）

A. To list all backups that were no longer available for restore operations
B. To list all backups that had aged beyond the RMAN retention criteria
C. To list all backup set pieces listed in control-file or recovery-catalog metadata that are not on the backup media
D. To list all datafiles that are no longer part of the database and thus do not need to be backed up
E. To list all archived redo logs that are no longer needed for any database recovery

单项选择题Whatistheresultofthiscommand？（）RMAN>Reportneedbackupdays3；

A. Lists all datafiles created in the last three days that are not backed up.
B. Lists all datafiles not recoverable based on the current retention criteria.
C. Lists all datafiles not backed up in the last three days. The datafile is not recoverable. 
D. Lists all datafiles that need to be backed up due to unrecoverable operations.
E. Lists all datafiles not backed up in the last three days. It does not imply that the datafile is not recoverable.

单项选择题What does the output on this report indicate？（）   RMAN> report need backup；  RMAN retention policy will be applied to the command  RMAN retention policy is set to redundancy 1  Report of files with less than 1 redundant backups  File #bkps Name  5 0 C： ORACLE ORADATA ORCL MY_DATA_01.DBF

A. The my_data_01.dbf datafile is corrupted and needs to be restored.
B. The my_data_01.dbf datafile has not yet been backed up. This report does not imply that the data in the datafile can not be recovered.
C. The my_data_01.dbf datafile has not yet been backed up. This report implies that the data in the datafile can not be recovered.
D. The my_data_01.dbf datafile no longer meets the retention criteria for backups.
E. Datafile 5 is missing.

单项选择题What is the impact of the results of the output of the following command？（）   RMAN> report unrecoverable database；  Report of files that need backup due to unrecoverable operations  File Type of Backup Required Name  4 full or incremental C： ORACLE ORADATA ORCL USERS01.DBF

A. There are no backup sets with any backups of the users01.dbf datafile.
B. The users01.dbf datafile has had unrecoverable operations occur in it. It will need to be backed up or some data loss is possible during a recovery.
C. The users01.dbf datafile is corrupted.
D. The users01.dbf datafile backup exceeds the retention criteria.
E. The last backup of the users01.dbf datafile failed and must be rerun.

单项选择题Whatviewmightyouusetotrytodeterminehowlongaparticularbackupwilltake？（）

A. V$SESSION_EVENT
B. V$SESSION
C. V$WAITS
D. V$WAITSTAT
E. V$SESSION_LONGOPS