Flashback Database relies on which technologies to recover to a point in time？（）  

多项选择题Which method could be utilized to identify both DML operations and the SQL statements needed to undo those operations for a specific schema owner？（）

A.A
B.B
C.C
D.D

单项选择题You have just performed a FLASHBACK TABLE operation using the following command：   flashback table employees to scn 123456；   The employees table has triggers associated with it.  Which of the following statements is true regarding the state of the triggers during the Flashback Table operation？（）

A. All the triggers are disabled.
B. All the triggers are enabled by default.
C. Enabled triggers remain enabled and disabled triggers remain disabled.
D. Triggers are deleted when a Flashback Table operation is performed.

单项选择题WhichofthefollowingstatementsistrueregardingimplementingaFlashbackTablerecovery？（）

A. An SCN is never used to perform a Flashback Table recovery.
B. If a significant number of changes have been made to the table， row movement must be enabled.
C. The tablespace must be offline before performing a Flashback Table recovery.
D. Flashback Table recovery is completely dependent on the availability of undo data in the undo  tablespace.

单项选择题WhichofthefollowingstatementsistrueregardingtheVERSIONSBETWEENclause？（）

A. The VERSIONS BETWEEN clause may be used in DML statements.
B. The VERSIONS BETWEEN clause may be used in DDL statements.
C. The VERSIONS BETWEEN clause may not be used to query past DDL changes to tables.
D. The VERSIONS BETWEEN clause may not be used to query past DML statements to tables.

单项选择题At the request of a user， you issue the following command to restore a dropped table： flashback table  BIN$F2JFfMq8Q5unbC0ceE9eJg==$0  to before drop； Later， the user notifies you that the data in the table seems to be very old and out of date.  What might be the problem？（）

A. Because a proper range of SCNs was not specified， the wrong data was restored.
B. A proper range of timestamps was not specified， so the wrong data was restored.
C. A previous Flashback Drop operation had been performed， resulting in multiple versions of the table being stored in the Recycle Bin.
D. Either option A or B could be correct. Not enough information was provided to determine which.
E. None of the above.