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 sta

第1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2题：

You need to ensure that the database users should be able to use the various flashback query features in order to go back in time by four hours. What would you do to achieve this?（）

• A、set SQL_TRACE=True 
• B、set UNDO_RETENTION=14400 
• C、set FAST_START_MTTR_TARGET=240 
• D、set LOG_CHECKPOINT_INTERVAL=240 
• E、set DB_FLASHBACK_RETENTION_TARGET=14400 
• F、set the RETENTION GUARANTEE clause for the undo tablespace

第3题：

第4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5题：

You must track all transactions that modify certain tables in the sales schema for at least three years. Automatic undo management is enabled for the database with a retention of one day. Which two must you do to track the transactions?（）

• A、Enable supplemental logging for the database.
• B、Specify undo retention guarantee for the database.
• C、Create a Flashback Data Archive in the tablespace where the tables are stored.
• D、Create a Flashback Data Archive in any suitable tablespace.
• E、Enable Flashback Data Archiving for the tables that require tracking

第6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7题：

You need to maintain a record of all transactions on some tables for at least three years. Automatic undo management is enabled for the database. What must you do accomplish this task？（）

• A、 Enable supplemental logging for the database.
• B、 Specify undo retention guarantee for the database
• C、 Create Flashback Data Archive in the tablespace where the tables are stored.
• D、 Create Flashback Data Archive and enable Flashback Data Archive for specific tables

第8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9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.