A user performs an update on a table. Shortly after committing the transaction， they realize that they had an error in their WHERE clause causing the wrong rows to be updated. Which Flashback option would allow you to undo this transaction and restore the

第1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

第2题：

Users notify you that their application is failing every time they try to add new records. Because of poor application design， the actual ORA error message is unavailable.  What might be the problem？（）

• A、 The application user has exceeded their undo quota.
• B、 The FLASHBACK GUARANTEE option is set on the undo tablespace.
• C、 The table is currently being queried by a Flashback Transaction Query operation.
• D、 The table is currently being queried by a Flashback Versions Query operation.
• E、 The RETENTION GUARANTEE option is set on the undo tablespace.

第3题：

第4题：

Which method would you use to undo the changes made by a particular transaction without affecting the changes made by other transactions?（）

• A、point-in-time recovery
• B、execute the ROLLBACK command with transaction number
• C、flashback the database to before the transaction was committed
• D、determine all the necessary undo SQL statements from FLASHBACK_TRANSACTION_QUERY and use them for recovery

第5题：

In which scenario will you use the Flashback Transaction Query feature？（）

• A、 when you want to restore an important table that is dropped from the Recycle Bin
• B、 when you want to obtain the SQL statements to undo the deletion of some important records from a table by a transaction
• C、when you want to restore a dropped user’s schema
• D、 when a row of a table is updated many times within a specific time period and you want all the versions of the row in the specified time period

第6题：

At 5：30 PM， a database administrator， William， is informed that an important record of employee no E0025 is missing from the SCOTT.EMPLOYEE table. At 4：30 P.M， the table contained the record of employee no E0025. William issues the following command to find the SQL statements that are used to undo the deletion：    SELECT operation， undo_sql， logon_user   FROM FLASHBACK_TRANSACTION_QUERY  WHERE xid=   HEXTORAW（’0100043E23456’）；   where ’0100043E23456’ is the transaction ID of the transaction that deleted the row. Before issuing the above statement， which task did William perform to identify the transaction ID of the transaction that deleted the row？（）

• A、 William used the Flashback Version Query feature.
• B、 William issued the CROSSCHECK command at the RMAN prompt.
• C、 William viewed the alert log file.
• D、 William used the Flashback Table feature.

第7题：

The session of user SCOTT receives the following error after executing an UPDATE command onthe EMP table：  ERROR at line 1：  ORA-00060： deadlock detected while waiting for resource  On investigation， you find that a session opened by user JIM has a transaction that caused the deadlock.  two statements are true regarding the session of SCOTT in this scenario（）

• A、The session is terminated after receiving the error and JIM can continue with his transaction.
• B、SCOTT should perform a COMMIT or ROLLBACK to allow JIM to continue with his transaction.
• C、The session is rolled back after receiving the error and JIM can continue with his transaction.
• D、SCOTT has to reexecute the last command in the transaction after he commits the transaction.

第8题：

You are employed as a DBA in an organization. You are informed that the record of EMP_NO 1000 is missing from the SCOTT.EMP table. You are required to identify the user who deleted the record， the SQL statement that will undo the deletion， and the transaction ID of the transaction that deleted the employee record. Which feature will you use to perform the tasks？（）

• A、 Only the Flashback Table
• B、 Both the Flashback Transaction Query and the Flashback Version Query
• C、 Only the Flashback Drop
• D、 Only the Flashback Version

第9题：

View the following SQL statements：   Transaction T1 INSERT INTO hr.regions VALUES （5，’Pole’）；COMMIT；  Transaction T2 UPDATE hr.regions SET region_name=’Poles’ WHERE region_id = 5； COMMIT；  Transaction T3 UPDATE hr.regions SET region_name=’North and South Poles’ WHERE region_id = 5；   You want to back out transaction T2.  Which option would you use？（）

• A、 It is possible，but transaction T3 also backs out.
• B、 It is possible with the NOCASCADE_FORCE option.
• C、 It is possible with the NONCONFLICT_ONLY option.
• D、 It is not possible because it has conflicts with transaction T3.

第10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