单选题Your database instance is configured with automatic undo management and the UNDO_RETENTIONparameter is set to 900 seconds. You executed the following command to enable retention guarantee: SQL> ALTER TABLESPACE undotbs1 RETENTION GUARANTEE;  What effec

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：

You specify a nonzero value for the MEMORY_TARGET initialization parameter，but do not set the PGA_AGGREGATE_TARGET or the SGA_TARGET parameters. You restart your database instance.  Which statement about the result is true？（）

• A、 The database instance starts，and Oracle sets the default value of SGA_TARGET to the same value as SGA_MAX_SIZE
• B、 The database instance starts，and Oracle automatically tunes memory and allocates 60 percent to the  SGA and 40 percent to the PGA
• C、 The database instance starts，but Automatic Memory Management is disabled
• D、 The database instance will not start because you did not specify the PGA_AGGREGATE_TARGET or SGA_TARGET parameter

第3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4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5题：

Your database instance is running with full workload after database creation. You have decided to use a fixed-size undo tablespace. You want to use the Undo Advisor to estimate the capacity of the undo tablespace. Which two factors must you consider before using the Undo Advisor to estimate the capacity of the undotablespace（）

• A、The retention period to support flashback
• B、The expected length of the longest-running query
• C、The number of undo tablespaces in the database
• D、The size of the Flash Recovery Area for the database instance

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：

Which are the prerequisites for performing flashback transactions on your database？（）

• A、 Undo retention guarantee for the database must be configured.
• B、 Supplemental log must be enabled for the primary key.
• C、 Supplemental log must be enabled.
• D、 Execute permission on the DBMS_FLASHBACK package must be granted to the user.

第8题：

Your database instance is running with full workload after database creation. You have decided to useafixed-sizeundo tablespace. You want to use the Undo Advisor to estimate the capacity of the undotablespace.  Which two factors must you consider before using the Undo Advisor to estimate the capacity of the undotablespace（）

• A、the retention period to support flashback
• B、the expected length of the longest-running query
• C、the number of undo tablespaces in the database
• D、the size of the Flash Recovery Area for the database instance

第9题：

In your production database you want to use an Automatic Storage Management （ASM） instance to manage the database files. Which option would you use to migrate the database files from a non-ASM instance to an ASM instance？（）

• A、Oracle Migration Assistant
• B、Recovery Manager （RMAN）
• C、Oracle Data Pump Export and Import
• D、conventional Oracle Export and Import
• E、operating system utilities to copy the files to the ASM instance

第10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.