多选题You are working on an Oracle Database 10g database. Because of data loss， you decided to perform a Flashback Database operation using the following command：  SQL FLASHBACK DATABASE TO TIMESTAMP（SYSDATE ？5/24）； Which two statements are true？ （）ASYSDATE 

第1题：

You are working on an Oracle Database 10g database. You enabled the Flashback Database feature. Which two statements regarding flashback logs are true？ （）

• A、 Flashback logs are not archived.
• B、 Flashback logs are maintained in redo log files.
• C、 Flashback logs are maintained in the Flash Recovery Area.
• D、 Flashback logs are used to maintain Flashback Database related errors.
• E、 Flashback logs need to be cleared manually after you disable Flashback Database.

第2题：

You are working on an Oracle Database 10g database. Because of data loss， you decided to perform a Flashback Database operation using the following command：  SQL> FLASHBACK DATABASE TO TIMESTAMP（SYSDATE 5/24）;  Which two statements are true？ （）

• A、SYSDATE should not be used with TIMESTAMP.
• B、The database must have multiplexed redo log files.
• C、The database must be in the MOUNT state to execute the command.
• D、The database must be opened with the RESETLOGS option after the flashback operation.
• E、The entire database needs to be restored from the most recent backup before the flashback operation.

第3题：

第4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

第5题：

You disabled the Flashback Database feature by using the following command：  SQL> ALTER DATABASE FLASHBACK OFF；  What would be the effect of this command on the existing flashback logs？（）

• A、 Flashback logs are not deleted.
• B、 Flashback logs are deleted automatically.
• C、 Flashback logs are deleted only if you are using Recovery Manager （RMAN）
• D、 Flashback logs are deleted only if you are using Oracle Manager Files （OFM）
• E、 Flashback logs are deleted only if you are using Automatic Storage Management （ASM）

第6题：

You are maintaining your OLTP database in Oracle10g. You are performing the Flashback Transaction Query to find the undo SQL statements that can be used to undo the changes made to the database in the specific time period. Which pseudocolumn will you use to perform the Flashback Transaction Query？（）

• A、 VERSIONS_STARTSCN
• B、 VERSIONS_STARTTIME
• C、 VERSIONS_XID
• D、 VERSIONS_OPERATION

第7题：

You plan to execute the following command to perform a Flashback Database operation in your database：   SQL> FLASHBACK DATABASE TO TIMESTAMP （SYSDATE -5/24）；   Which two statements are true about this？（）

• A、 The database must have multiplexed redo log files
• B、 The database must be in the MOUNT state to execute the command
• C、 The database must be in the NOMOUNT state to execute the command
• D、 The database must be opened in RESTRICTED mode before this operation
• E、 The database must be opened with the RESETLOGS option after the flashback operation

第8题：

第9题：

You can use Oracle Flashback to look at past activity in your database. What are two other characteristics of Oracle Flashback？（）

• A、Oracle Flashback uses undo information to construct consistent data. 
• B、You can use a cursor opened while using an Oracle Flashback image to perform DML once you deactivate Oracle Flashback in your session. 
• C、You can only use Oracle Flashback view of the data if the required records are still in the online redo log files. 
• D、Oracle Flashback lists the DML that was executed during the period you identify when initiating your session. 

第10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.