You executed the following command to perform a backup of the USERS tablespace： 
SQL> ALTER TABLESPACE users BEGIN BACKUP；
ALTER TABLESPACE users BEGIN BACKUP * 
ERROR at line 1： 
ORA-01123： cannot start online backup； media recovery not enabled 
What could be the reason for this error（）

单项选择题WhichstatementistrueaboutawholeconsistentdatabasebackuponadatabaserunninginARCHIVELOGmode（）

A.The backup will consist of used data blocks only.
B.The database must be shut down to accomplish the backup.
C.The backup can be accomplished without shutting down the database.
D.The backup will contain all database files that have never been backed up.

单项选择题Your test database is configured to run in NOARCHIVELOG mode. One of the data files in the USERStablespace is lost due to a media failure. You notice that all the online redo logs have been overwritten since the last backup.  What would you do to recover the data file（）

A.Take the USERS tablespace offline and re-create the lost data file.
B.Shut down the instance， restore the data file from the last consistent backup， and restart the databaseinstance.
C.Shut down the instance， restore all the database files from the last consistent backup， and restart thedatabase instance.
D.Take the USERS tablespace offline， restore all the data files of the USERS tablespace from the lastconsistent backup， and make the tablespace online.

单项选择题The database is running in ARCHIVELOG mode. Examine the initialization parameters and theirvalues set to enable archiving on your database server：  LOG_ARCHIVE_FORMAT = arch_%t_%s_%r.arc  LOG_ARCHIVE_DEST_1 = ’LOCATION =  disk1 archive’  DB_RECOVERY_FILE_DEST = ’ u01 oradata’  DB_RECOVERY_FILE_DEST_SIZE = 20G  Which statement is true regarding the archived redo log files（）

A.It will be created on the local file system.
B.It will be created only in the Flash Recovery Area.
C.It will be created in the location specified by the LOG_ARCHIVE_DEST_1 parameter and the defaultlocation $ORACLE_HOME/dbs.
D.It will be created in the location specified by the LOG_ARCHIVE_DEST_1 parameter and locationspecified by the DB_RECOVERY_FILE_DEST parameter.

多项选择题You are managing an Oracle Database 11g database. You configured the database to run inARCHIVELOG mode.  Which two statements are true in this scenario（）

A.You must shut down the database instance to perform the backups.
B.You must configure the Flash Recovery Area （FRA） for the database.
C.You can perform complete database backups without closing the database.
D.All the previous closed database backups including control files become invalid after you configure thedatabase to ARCHIVELOG mode.

单项选择题You want to enable archiving on your database. Presently， the database is running inNOARCHIVELOG mode. Given below are the steps to accomplish the task in random order：  1：Shut down the instance.  2：Execute the ALTER DATABASE ARCHIVELOG command.  3：Start up the instance and mount the database.  4：Set the DB_RECOVERY_FILE_DEST initialization parameter to $ORACLE_HOME dest_1. 5： Open the database.  Which is the correct sequence of steps for accomplishing the task（）

A.4，1，3，2，5
B.1，3，4，5，2
C.1，3，2，5；4 not required
D.4，1，5，2；3 not required
E.1，3，4，5；2 not required