单选题What is true regarding a transaction executed in Automatic Undo Management mode？（）A AB BC CD D

第1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2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3题：

第4题：

SORT_AREA SIZE and HASH_AREA_SIZE parameters are ignored in some of the user sessions. What could be the reason？（）

• A、The User Global Area （UGA） is not configured.
• B、The sessions were started using the login name SYS.
• C、The sessions are running in the Automatic Shared Memory Management mode.
• D、The sessions are running in the automatic Program Global Area （PGA） memory management mode.

第5题：

You executed the following query：  SELECT operation， undo_sql， table_name FROM flashback_transaction_query； Which statement is correct regarding the query output？（）

• A、 It would return information regarding only the last committed transaction.
• B、 It would return only the active transactions in all the undo segments in the database.
• C、 It would return only the committed transactions in all the undo segments in the database.
• D、 It would return both active and committed transactions in all the undo segments in the database.
• E、 It would return information regarding the transactions that began and were committed in the last 30 minutes.

第6题：

You started a long transaction. Before committing， you executed a query on one of the tables currently being modified. You received the following error： ORA-01555： snapshot too old How would you prevent such an error in the future？（）

• A、guarantee undo retention
• B、add one more redo log group
• C、size the redo log files appropriately
• D、size the UNDO tablespace appropriately
• E、size the SYSTEM tablespace appropriately
• F、configure an appropriate undo retention interval
• G、change automatic undo management to manual

第7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8题：

第9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).

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.