多选题Which two statements are true regarding transactions in an Oracle database（）AMultiple transactions can use the same undo segment.BA transaction is assigned an undo segment when it is started.CMore than one transaction cannot share the same extent in th

第1题：

Which two statements are true about interoperating with Oracle AQ JMS with Oracle WebLogic server ？（）

• A、 If you select a non-XA JDBC driver， you can use WebLogic AQ JMS in both local & global transactions
• B、 Oracle WebLogic Server requires a JDBC driver to communicate with the Oracle AQ JMS
• C、 Oracle WebLogic AQ JMS stand-alone client automatically participate in global transactions managed by Oracle WebLogic Server
• D、 If you select an XA JDBC driver， you can use WebLogic AQ JMS in both local and global transactions

第2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3题：

第4题：

What is true if you want to switch undo tablespaces from the current one， called UNDO1， to a new one called UNDO2？（）

• A、It is NOT possible to switch unless no active transaction exist in UNDO1. 
• B、It is possible to switch to UNDO2； but current active transactions will abort. 
• C、It is possible to switch to UNDO2； current active transactions will be automatically migrated to UNDO2. 
• D、It is possible to switch to UNDO2； only current active transactions will continue to execute inside UNDO1.

第5题：

You receive complaints from users regarding the high waiting time for their transactions. Oninvestigation， you find that some users are not committing their transactions though they are  notperforming any activity for a long time. As a result， SQL statements need to wait for row-level locks.  Which two actions could you take to prevent this locking problem in the future（）

• A、Decrease the IDLE_TIME resource limit in the profile assigned to the blocking users.
• B、Use Database Resource Manager to automatically log out sessions that block others and are idle.
• C、Set the limit in the profile of blocking users to control the number of blocks to be accessed in a session.
• D、Decrease the maximum number of interested transaction list （ITL） slots for the segments on which the blocking user performs the transaction

第6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7题：

Which method would you use to undo the changes made by a particular transaction without affecting the changes made by other transactions?（）

• A、point-in-time recovery
• B、execute the ROLLBACK command with transaction number
• C、flashback the database to before the transaction was committed
• D、determine all the necessary undo SQL statements from FLASHBACK_TRANSACTION_QUERY and use them for recovery

第8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9题：

Which two statements are true regarding transactions in an Oracle database（）

• A、Multiple transactions can use the same undo segment.
• B、A transaction is assigned an undo segment when it is started.
• C、More than one transaction cannot share the same extent in the undo tablespace.
• D、The transactions use system undo segment to store undo data if all the segments in the undo tablespaceare used.

第10题：

You set the undo pool resource plan directive for the consumer group named DSS_USERS that is assigned to the DAY_SHIFT plan. The database users， SCOTT and BLAKE， belong to the DSS_USERS resource group. The user， SCOTT， initiates a database session and executes a batch operation that inserts millions of rows into the HISTORY table. Which two options are true if the total undo space allocated to the DSS_USERS group exceeds the value specified in the undo pool resource plan directive？（）

• A、 The batch operation started by the user， SCOTT， terminates with an error.
• B、 The batch operation started by the user， SCOTT， hangs and you are required to increase the undo pool resource plan directive.
• C、 The batch operation started by the user， SCOTT， runs uninterrupted because the database uses the SYSTEM tablespace for the undo operation.
• D、 The user， BLAKE， cannot start a transaction that uses any DML operations until you increase the value of the undo pool resource plan directive.
• E、 The user BLAKE can start a transaction that uses any DML operations after the batch operation started by the user， SCOTT， terminates with an error.