单选题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 

第1题：

You are working in a dedicated server environment. Your database is running in the automatic Program Global Area （PGA） memory management mode. Which two statements are correct in this scenario？ （）

• A、 The WORK_AREASIZE_POLICY initialization parameter cannot be set to AUTO.
• B、 The Oracle database automatically controls the amount of PGA memory allotted to SQL work areas.
• C、 Setting the value of the SGA_TARGET initialization parameter to 0 will disable the automatic PGA memory management.
• D、 The SORT_AREA_SIZE parameter is ignored by all the sessions running in the automatic PGA memory management mode.

第2题：

Identify three key features of ASM.（）

• A、file striping
• B、allocation unit mirroring
• C、automatic disk rebalancing
• D、automatic file size increment
• E、automatic undo management

第3题：

第4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5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6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7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8题：

第9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10题：

Which are the two prerequisites before setting up Flashback Data Archive? （）(Choose two.)

• A、Flash recovery area must be defined
• B、Undo retention guarantee must be enabled.
• C、Database must be running in archivelog mode.
• D、Automatic undo management must be enabled.
• E、The tablespace in which the Flashback Data Archive is created must have automatic segment space Management (ASSM).