单选题You work as a database administrator for Certkiller .com. One of the user sessions was terminated abnormally in the middle of a transaction. What does Oracle database do to recover it？（）A Uses undo data for roll forwardB Uses Flashback Log for recovery

第1题：

You work as a database administrator for Certkiller .com. One of the user sessions was terminated abnormally in the middle of a transaction. What does Oracle database do to recover it？（）

• A、Uses undo data for roll forward
• B、Uses Flashback Log for recovery
• C、Uses online redo logs to roll back
• D、Uses undo data to roll back the transaction
• E、Uses Recovery Manager （RMAN） to roll back
• F、Uses the System Monitor （SMON） background process to perform instance recovery

第2题：

You work as a database administrator for Certkiller .com. Your database is in NOARCHIVELOG mode. The database has been configured with three redo logs groups， and there have been five log switches. You lost one non-system-critical data file from your database.  Which method would you use to recover the data file？（）

• A、Restore all the data files and open the database
• B、Create the data file and performtablespacerecovery
• C、No need to restore any file， just recover the database
• D、Restore only the system data file and recover the database
• E、Restore only lost date file and performtablespacerecovery

第3题：

You work as a database administrator for Certkiller .com. You received the following error while working on your database： ORA-01555： snapshot too old  In which situation would you receive such an error？（）

• A、You performed rollback after commit.
• B、If a log switch occurs in your database.
• C、Thearchiverfails to generate an archived log file.
• D、Instance recovery fails to find one of the redo log files.
• E、A long-running query is unable to get read-consistent image.
• F、If you perform manual undo management operations in auto mode.

第4题：

You work as a database administrator for Certkiller .com. On a Monday morning， you find the database instance aborted. After inspecting the alert log file， you execute the STARTUP command in SQL*Plus to bring the instance up. What statement is true？（）

• A、PMON coordinates media recovery.
• B、SMON coordinates instance recovery.
• C、PMON coordinates instance recovery.
• D、Undo Advisor would roll back all uncommitted transactions.
• E、SQL*PLUS reports an error with the message asking you to perform instance recovery. 

第5题：

You work as a database administrator for Certkiller .com. Users in the Certkiller .com PROD database complain about the slow response of transactions. While investigating the reason you find that the transactions are waiting for the undo segments to be available， and undo retention has been set to zero. What would you do to overcome this problem？（）

• A、Increase the undo return
• B、Create more undo segments
• C、Create another undotablespace
• D、Increase the size of the undotablespace

第6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7题：

Which three statements are true about Flashback Database?（）

• A、Flashback logs are written sequentially, and are archived.
• B、Flashback Database uses a restored control file to recover a database.
• C、The Oracle database automatically creates, deletes, and resides flashback logs in the Fast Recovery Area.
• D、Flashback Database can recover a database to the state that it was in before a reset logs operation.
• E、Flashback Database can recover a data file that was dropped during the span of time of the flashback.
• F、Flashback logs are used to restore to the blocks' before images, and then the redo data may be used to roll forward to the desired flashback time.

第8题：

You work as a database administrator for Supportcenter.cn. One of the user sessions was terminated abnormally in the middle of a transaction. What does Oracle database do to recover it？（）

• A、Uses undo data for roll forward
• B、Uses Flashback Log for recovery
• C、Uses online redo logs to roll back
• D、Uses undo data to roll back the transaction
• E、Uses Recovery Manager （RMAN） to roll back
• F、Uses the System Monitor （SMON） background process to perform instance recovery

第9题：

One of the user sessions was terminated abnormally in the middle of a transaction. What does Oracle database do to recover it？（）

• A、uses undo data for roll forward
• B、uses Flashback Log for recovery
• C、uses online redo logs to roll back
• D、uses undo data to roll back the transaction
• E、uses Recovery Manager （RMAN） to roll back
• F、uses the System Monitor （SMON） background process to perform instance recovery

第10题：

You work as a database administrator for Certkiller .com. In the middle of a transaction， a user session was abnormally terminated but the instance is still up and the database is open. Which two statements are true in this scenario？（）

• A、Event Viewer gives more details on the failure.
• B、The alert log file gives detailed information about the failure.
• C、PMON rolls back the transaction and releases the locks.
• D、SMON rolls back the transaction and releases the locks.
• E、The transaction is rolled back by the next session that refers to any of the blocks updates by the failed transaction.
• F、Data modified by the transaction up to the last commit before the abnormal termination is retained in the database.