You have used the CROSSCHECK BACKUP command to verify that the backups recorded in the RMAN repository actually exist. 
Which command should you now use to check if any of the files were missing？（）

单项选择题WhatdoestheCharacterSetScannercommandlineutilitydo？（）

A.Reports only on any Unicode character conversions required.
B.Performs character set conversions to the new specified character set.
C.Scans on any character set conversion required， then converts the data.
D.Checks for any character definitions that will fail conversion to the new character set.

多项选择题Oracle9i provides a database package called dbms_redefinition to perform an online rebuild of a table.  Which two steps are you recommended to do prior to issuing thedbms_redefinition_start_redef table procedure call？（）

A.Grand privileges on the interim table.
B.Invoke the dbms_redefinition.can_redef_table procedure.
C.Invoke the dbms_redefinition.sync_interim_table procedure.
D.Create any triggers， indexes， or constraints on the interim table.
E.Create an empty interim table with all the desired characteristics.

单项选择题Youareresponsibleforadatawarehouseapplicationthatusesrecordsfromanexternaltabletoupdateoneofthedimensiontablesperiodically.Therecordsintheexternaltablemaycontaindatafornewrowsinthedimensiontable，orforupdatestoitsexistingrows.WhichtypeofSQLcommandwouldyouusetotransferthedatafromtheexternaltabletothedimensiontableasefficientlyaspossible？（）

A.MERGE
B.SELECT …CROSS JOIN
C.INSERT ALL …SELECT
D.CREATE VIEW …CONSTRAINT

单项选择题WhatdoestheMetadataApplicationProgrammingInterface（API）allowyoutodo？（）

A.Repair damaged data dictionary entries.
B.Delete data dictionary information about database objects you no longer need.
C.Extract data definition commands from the data dictionary in a variety of formats.
D.Prepare pseudocode modules for conversion to Java or PL/SQL programs with a Metadata code generator

单项选择题The list below displays four steps that you need to execute in order to switch from the primary database role to the standby database role. Choose the correct order of execution for the steps.（）  1. Shot down and start up the former primary instance without mounting the instance.  2. Issue the ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL  STANDBY command.  3. Issue the ALTER DATABASE MOUNTS STANDBY DATABASE command.  4. End read or update activity on the former primary and standby database.

A.1，2，3，4
B.3，2，4，1
C.4，2，1，3
D.4，3，2，1