单选题You have a long-running process you want to assign to a specific UNDO segment brought online for that express purpose. You are not using automatic UNDO management. What statement can be used for this task? （）A ALTER DATABASE B SET TRANSACTION C ALTER R

第1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2题：

You have not configured Oracle Managed Files （OMF） in your database. You do not want to scan the entire datafile every time an incremental backup is performed. You decide to enable the block change tracking feature. Which statement will you use to enable the block change tracking feature？（）

• A、 ALTER SYSTEM ENABLE BLOCK CHANGE TRACKING；
• B、 ALTER DATABASE ENABLE BLOCK CHANGE TRACKING；
• C、 ALTER SYSTEM ENABLE BLOCK CHANGE TRACKING USING FILE ；
• D、 ALTER DATABASE ENABLE BLOCK CHANGE TRACKING USING FILE ；

第3题：

第4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 shrinking the SCOTT.EMP table by executing the ALTER TABLE SCOTT.EMP SHRINK SPACE CASCADE statement. What is a prerequisite for shrinking the SCOTT.EMP table？（）

• A、 You must enable the block change tracking feature.
• B、 You must have enable the flashback feature.
• C、 You must use the OMF in your database.
• D、 You must define the tablespace of the SCOTT.EMP table for automatic segment space management.

第7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8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：

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

• A、The extents in the undo tablespace retain data until the next full database backup.
• B、The extents containing committed undo in the undo tablespace are not overwritten for at least 15minutes.
• C、The extents containing committed data in the undo tablespace are not overwritten until the instance isshut down.
• D、The extents containing committed undo in the undo tablespace are transferred to Flash Recovery Areabefore being overwritten.