单选题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 autoextensibleB When there are more than one undo tablespaces available in the databaseC When the undo tablespac

第1题：

Which two statements are true regarding undo tablespaces（）

• A、The database can have more than one undo tablespace.
• B、The UNDO_TABLESPACE parameter is valid in both automatic andmanualundo management.
• C、Undo segments automatically grow and shrink as needed， acting as circular storage buffer for their assigned transactions.
• D、An undotablespaceis automatically created if the UNDO_TABLESPACEparameter is not set and the UNDO_MANAGEMENT parameter is set to AUTO during the database instance start up.

第2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：

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5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6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7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8题：

When youre performing a tablespace point-in-time recovery， which tablespaces will always be restored to the auxiliary instance？（）

• A、 The SYSTEM tablespace.
• B、 The UNDO tablespace.
• C、 All tablespaces with tables.
• D、 All tablespaces with indexes.
• E、 No tablespaces are automatically restored.

第9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10题：

Which two statements are true regarding transactions in an Oracle database（）

• A、Multiple transactions can use the same undo segment.
• B、A transaction is assigned an undo segment when it is started.
• C、More than one transaction cannot share the same extent in the undo tablespace.
• D、The transactions use system undo segment to store undo data if all the segments in the undo tablespaceare used.