Your database is functioning in ARCHIVELOG mode. In which two situations would you perform a cancel­based recovery？（）

单项选择题You have only two redo log groups and these groups get overwritten several times in a day. Your database operates in NOARCHIVELOG mode and user­managed consistent backups are performed every Sunday night. On Thursday morning， you find that an important table has been dropped and purged.  With reference to this scenario， up to what point in time can the data be recovered？（）

A.until Thursday morning
B.until last Sunday’s backup
C.until Wednesday evening
D.until that point in time when the database is opened
E.until that point in time when the recovery is performed
F.until that point in time when the table is dropped and purged

单项选择题YourdatabaseoperatesinARCHIVELOGmodeanduser­managedconsistentbackupsareperformedeverySundaynight.OnTuesday，at9：00a.m.thecurrentlogsequencenumberwas369.Also，onTuesdayyoulostthedatafilebelongingtotheSYSTEMtablespaceandanarchivelogfile（sequencenumber356）thatcontainedredoentriesbetween8：00a.m.and8：30a.m.Withreferencetothisscenario，whatwouldyoudotorecoverthedatabase？（）

A.restore all the data files from last Sunday’s backup， and then perform a time­based recovery
B.restore all the data files from last Sunday’s backup， and then perform a cancel­based recovery
C.restore all the data files from last Sunday’s backup， and then perform a change­based recovery
D.restore only data files that belong to the SYSTEM tablespace from last Sunday’s backup， and then perform a complete recovery

单项选择题Your database operates in ARCHIVELOG mode. User­managed consistent backups are performed every Sunday night.  On Tuesday， client A drops a table at 8：00 a.m. as follows：  SQL> DROP TABLE cust_ord PURGE  Table dropped.  Client B executes a query at 9：00 a.m. on the same table as follows：  SQL> SELECT * FROM cust_ord SELECT * FROM cust_ord *  ERROR at line 1：  ORA­00942： table or view does not exist  Client B needs the dropped table and reports the problem to you. With reference to this scenario， which action should you take？（）

A.retrieve the table by using the flashback feature
B.restore all the data files from last Sunday’s backup， and then perform a time­based recovery
C.restore all the data files from last Sunday’s backup， and then perform a log sequence recovery
D.restore all the data files from last Sunday’s backup， and then perform a cancel­based recovery
E.restore from last Sunday’s backup only data files that belong to the tablespace in which the table was stored， and then perform a complete recovery

多项选择题You are connected to Recovery Manager （RMAN） without a recovery catalog. There is no copy of the control file available. You want to restore the control file from an autobackup. To retrieve the autobackup，you need the database ID （DBID）.  In which two sources would you find the DBID？ （）

A.the trace file
B.the alert log file
C.an RMAN session log file
D.the server parameter file
E.the formatted name of a control file autobackup

多项选择题You used the following command in Recovery Manager （RMAN） as part of the recovery process： RESTORE CONTROLFILE FROM AUTOBACKUP  How does RMAN find the control file autobackup？（）

A.by using the trace file
B.by using the alert log file
C.by using the database ID
D.by using the server parameter file
E.by using the V$CONTROLFILE view
F.by using the autobackup format configuration setting