By using the transaction identifier provided by （） for a particular row change， you can use theFlashback Transaction Query to see the operation performed by the transaction. 

单项选择题You executed the following query： SELECT operation， undo_sql， table_name FROM flashback_transaction_query；  Which statement is correct regarding the query output？（）

A.It would return information regarding only the last committed transaction.
B.It would return only the active transactions in all the undo segments in the database.
C.It would return only the committed transactions in all the undo segments in the database.
D.It would return both active and committed transactions in all the undo segments in the database.
E.It would return information regarding the transactions that began and were committed in the last 30 minutes.

单项选择题By mistake， you ran the batch job （for updating the BILL_DETAILS table） twice. You are not sure which rows in the BILL_DETAILS table were affected. You need to identify：  a） a list of changes made along with the transaction identifier of each change  b） the necessary SQL statements to undo the erroneous changes  Which option would you choose？（）

A.RMAN only
B.Flashback Table only
C.Flashback Versions Query only
D.Flashback Database and Flashback Transaction Query
E.Flashback Versions Query and Flashback Transaction Query

单项选择题View the Exhibits. You performed operations on the DEPT4 table as shown in the Exhibit. When you perform the FlashbackVersions Query， you find that the first two updates are not listed. What could be the reason？（）

A.The row movement is not enabled on the table.
B.The first two updates were not explicitly committed.
C.The Flashback Versions Query lists only the most recent update.
D.The Flashback Versions Query stops producing rows after it encounters a time in the past when the  table structure was changed.

单项选择题You are working in an online transaction processing （OLTP） environment. You realize that the salary for an employee， John， has been accidentally modified in the EMPLOYEES table. Two days ago， the data was in the correct state. Flashback logs generated during last two days are available in the flash recovery area.  Which option would you choose to bring the data to the correct state while ensuring that no other data in the same table is affected？（）

A.perform point-in-time recovery
B.perform a Flashback Table operation to restore the table to the state it was in two days ago
C.perform a Flashback Database operation to restore the database to the state it was in two days ago
D.perform Flashback Versions Query and Flashback Transaction Query to determine all the necessary undo SQL statements， and then use them for recovery

多项选择题ForwhichtwoSQLstatementscanyouusetheFlashbackTablefeaturetorevertatabletoitspreviousstate？（）

A.UPDATE TABLE
B.CREATE CLUSTER
C.TRUNCATE TABLE
D.ALTER TABLE MOVE
E.INSERT INTO···VALUES
F.ALTER TABLE···DROP COLUMN
G.ALTER TABLE···DROP PARTITION