You want to rebuild a free list in the free lists of the EMPLOYEE table in the Scott schema. Which package will you use to accomplish this？（）

单项选择题You issue the following statement：   SQL> SELECT FIRSTNAME， LASTNAME FROM HR.EMPLOYEE；  You receive the following error：         01578： ORACLE data block corrupted （file# 6， block # 54）        ORA-01110 ： data file 6： ’u01 oracle oradata data1.dbf’   How will you resolve this problem of data block corruption by reducing the mean time to recover （MTTR）？（）

A. by using the DBMS_REPAIR package
B. by using the DBVERIFY utility
C. by using Block Media Recovery
D. by issuing the ANALYZE TABLE HR.EMPLOYEES VALIDATE STRUCTURE command

单项选择题The datafiles of your database are ASM files. You are performing a check for datafile block corruption by using the DBVERIFY utility.   What is a prerequisite for checking block corruption on an ASM datafile by using the DBVERIFY utility？（）

A. The block change tracking feature must be enabled.
B. OMF must be configured on your database.
C. The database must be in ARCHIVELOG mode.
D. A USERID must be supplied.

单项选择题YouaremaintainingthePRODdatabaseofTeleSoftCorporation.YouhaveinitializedthefollowingDB_BLOCK_CHECKINGparameterintheinit.orafile：DB_BLOCK_CHECKING=TRUE；Whatwillbetheresultofsettingthisparameter？（）

A. Only data blocks of the SYSTEM tablespace will be checked.
B. Only data blocks of the SYSAUX tablespace will be checked.
C. A checksum will occur only on the checkpoint.
D. A checksum will occur every time a block is modified.

单项选择题YouareusingtheBlockMediaRecoveryfeaturetorecovertheblocksthataremarkedcorruptsincethelastbackup.Whichviewwillyouquerytodisplayinformationaboutthedatablocksthataremarkedcorruptsincethelastbackup？（）

A. V$BACKUP_CORRUPTION
B. V$COPY_CORRUPTION
C. V$DATABASE_BLOCK_CORRUPTION
D. RC_BACKUP_CORRUPTION

单项选择题YouaremaintainingyourOLTPdatabaseinOracle10g.YouareperformingtheFlashbackTransactionQuerytofindtheundoSQLstatementsthatcanbeusedtoundothechangesmadetothedatabaseinthespecifictimeperiod.WhichpseudocolumnwillyouusetoperformtheFlashbackTransactionQuery？（）

A. VERSIONS_STARTSCN
B. VERSIONS_STARTTIME
C. VERSIONS_XID
D. VERSIONS_OPERATION