单选题In your database， UNDO_RETENTION has been set to 600 sec and UNDO tablespace is configured for RETENTION GUARANTEE. Which statement regarding RETENTION GUARANTEE is true？ （）A Undo data is retained until the next full database backup.B No committed undo

第1题：

In which situation may the UNDO_RETENTION parameter be ignored， even if it is set to a value（）

• A、when the data file of the undo tablespace is autoextensible
• B、when there are more than one undo tablespaces available in the database
• C、when the undo tablespace is of a fixed size and retention guarantee is not enabled
• D、when the undo tablespace is autoextensible and retention guarantee is not enabled

第2题：

In your database， UNDO_RETENTION has been set to 600 sec and UNDO tablespace is configured for RETENTION GUARANTEE. Which statement regarding RETENTION GUARANTEE is true？ （）

• A、Undo data is retained until the next full database backup.
• B、No committed undo data will be overwritten for 10 minutes.
• C、Committed undo data will be kept forever if not overwritten within 600 seconds.
• D、Guarantees that requested undo information are available until the instance is shut down.

第3题：

In which situation is the UNDO_RETENTION parameter be ignored， even if it is set to a value（）

• A、When the data file of the undo tablespace is autoextensible
• B、When there are more than one undo tablespaces available in the database
• C、When the undo tablespace is of a fixed size and retention guarantee is not enabled
• D、When the undo tablespace is autoextensible and retention guarantee is not enabled

第4题：

Which statement is true about the UNDO_RETENTION parameter when retention guarantee is notenabled（）

• A、It is the time period after which the undo data becomes obsolete.
• B、It is the time period after which the committed undo data would be transferred to a temporarytablespace.
• C、It is the minimum time period up to which the committed undo data would be retained if free undo spaceis available.
• D、It is the time period after which the undo data is transferred to the Flash Recovery Area to provide readconsistency.

第5题：

Your database is running under automatic undo management and the UNDO_RETENTION parameter is set to 900 sec. You executed the following command to enable retention guarantee：  SQL> ALTER TABLESPACE undotbs1 RETENTION GUARANTEE;  What effect would this statement have on the database？（）

• A、The extents in undo tablespace retain data until the next full database backup.
• B、The extents containing committed data in the undo tablespace are never overwritten.
• C、The extents which no longer contain uncommitted data in the undo tablespace are not overwritten for at least15 minutes.
• D、The extents containing committed data in the undo tablespace are not overwritten until the instance  is shut down.

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：

You work as a database administrator for Certkiller .com. You want to create your database with the automatic undo management feature enable.Which two tasks must you perform to achieve this？（）

• A、Set the UNDO_RETENTION parameter to AUTO.
• B、Create an initial undo segment in undotablespace.
• C、Set the UNDO_RETENTION parameter to 900 or more
• D、Set the initialization parameter UNDO_MANAGEMENT to AUTO
• E、Set the UNDO_MANAGEMENT parameter to the name of an undotablespace

第8题：

You are maintaining your database in Oracle10g. You set the value of the UNDO_RETENTION initialization parameter to zero in the initialization parameter file. What will be the impact of specifying this setting？（）  

• A、 The database will not start.
• B、 The database will start but will not retain the undo data in the undo segment.
• C、 The database will start， and the undo segment will contain the undo data for at least one hour.
• D、 The database will start， and the undo segment will retain the undo data for at least 15 minutes.

第9题：

You work as a database administrator for Certkiller .com. The UNDO_RETENTION parameter in your database is set to 1000 and undoretention is not guaranteed. Which statement regarding retention of undo data is correct？（）

• A、Undo data becomes obsolete after 1，000 seconds.
• B、Undo data gets refreshed after 1，000 seconds.
• C、Undo data will be stored permanently after 1，000 seconds.
• D、Committed undo data would be retained for 1，000 seconds if free undo space is available.
• E、Undo data will be retained in the UNDOtablespacefor 1，000 seconds， then it gets movedmovedto the TEMPORARYtablespaceto provide read consistency.

第10题：

You require the Oracle server to manage the undo segments and space among various active sessions automatically. You created an undo tablespace， UNDO_TBS1， in your database. Which two additional steps would you perform to achieve this？（）

• A、Set the UNDO_RETENTION parameter to 900 or more.
• B、Create an initial undo segment in the undo tablespace.
• C、Enable the retention guarantee for the undo tablespace.
• D、Set the UNDO_TABLESPACE parameter to UNDO_TBS1.
• E、Set the UNDO_MANAGEMENT initialization parameter to AUTO.