多选题You need to ensure that the database users should be able to use the various flashback query features in order to go back in time by four hours. What would you do to achieve this?（）Aset SQL_TRACE=TrueBset UNDO_RETENTION=14400Cset FAST_START_MTTR_TARGET

第1题：

You want to use the Flashback Transaction Query feature to identify all the changes made to your database within a specific time period. What is a prerequisite for using the Flashback Transaction Query feature？（）

• A、 You must use automatic undo management in the database.
• B、 You must configure OMF in your database.
• C、 You must configure ASM for storing the datafiles.
• D、 You must multiplex the online redo log file.

第2题：

You have a database with the following tablespaces： SYSTEM， SYSAUX， UNDO， USERS， TEMP. You want to"roll back" the data in the USERS tablespace to the way it looked yesterday.  Which tablespaces do you need to perform a point-in-time restore operation on in order to complete this task？（） 

• A、 SYSTEM
• B、 SYSAUX
• C、 UNDO
• D、 USERS
• E、 TEMP
• F、 This restore is not possible

第3题：

第4题：

You executed the following query in your database： SELECT oldest_flashback_scn， oldest_flashback_time FROM V$FLASHBACK_DATABASE_LOG； What would you determine from the output？（）

• A、 The time when the last flashback operation in your database was performed.
• B、 The time when the first flashback operation in your database was performed.
• C、 A list of flashback operations performed in your database using SCN and time.
• D、 The approximate time and the lowest system change number （SCN） to which you can flash back your database.

第5题：

You work as a database administrator for Supportcenter.cn. One of the database users accidentally deleted all the rows of a critical table and committed the delete at 1：30 p.m. You senior database administrator， SupportCenter， asks you to retrieve the lost data. Which two actions would you use to ensure that there is no impact on other connected users while retrieving the deleted rows？（）

• A、Use a flashback query to retrieve the rows that were deleted
• B、Useconventialincremental export and then import the affected object
• C、Shutdown the database inNORMALmode and restart the database instance
• D、Use DBMS_META package to reconstruct the object using undo segments
• E、UseTablespacePoint in Time Recovery （TSPITR） method to recover the table and the data
• F、Use Oracle DataPumptwithflashback_timeoption toentableflashback export and then import the affected object.

第6题：

You need to ensure that the database users should be able to use the various flashback query features in order to go back in time by four hours. What would you do to achieve this?（）

• A、set SQL_TRACE=True 
• B、set UNDO_RETENTION=14400 
• C、set FAST_START_MTTR_TARGET=240 
• D、set LOG_CHECKPOINT_INTERVAL=240 
• E、set DB_FLASHBACK_RETENTION_TARGET=14400 
• F、set the RETENTION GUARANTEE clause for the undo tablespace

第7题：

On Friday at 11:30 am you decided to flash back the database because of a user error that occurred at 8:30 am. Which option must you use to check whether a flashback operation can recover the database to the specified time? （）

• A、Check the alert log file
• B、Query the V$FLASHBACK_DATABASE_LOG view
• C、Query the V$RECOVERY_FILE_DEST_SIZE view
• D、Query the V$FLASHBACK_DATABASE_STAT view
• E、Check the value assigned for the UNDO_RETENTION parameter

第8题：

第9题：

You work as a database administrator for Certkiller .com. Your database is configured for automatic undo management. UNDO_RETENTION is set to 3 hours. You want to flash back a table that was created last year. How far back can the flashback query go？ （）

• A、3 hours
• B、6 months
• C、until last year
• D、until last commit
• E、until the point when the undotablespacewas refreshed
• F、until the database is shut down and the memory erased

第10题：

You are working in an online transaction processing （OLTP） environment. You used the FLASHBACK TABLE command to flash back the CUSTOMERS table. Before executing the FLASHBACK TABLE command， the System Change Number （SCN） was 663571. After flashing back the CUSTOMERS table， you realize that the table is not in the correct state and the resultant changes are not what you had desired. So， you need to reverse the effects of the FLASHBACK TABLE command while ensuring that：  a） No other user data in the database is affected.  b） The operation takes the minimum possible time.  Which option would you choose？（）

• A、use the ROLLBACK command with SCN 663571
• B、perform Flashback Transaction Query with SCN 663571
• C、execute the FLASHBACK DATABASE statement to retrieve the CUSTOMERS table as it was at SCN 663571
• D、execute another FLASHBACK TABLE statement to retrieve the CUSTOMERS table as it was at SCN 663571