undo操作是（）
undo操作是（）
相关考题：
系统故障恢复的步骤是A．反向扫描日志文件、对每一个更新操作执行逆操作，如此下去B．对每一个更新操作执行逆操作、反向扫描日志文件，如此下去C．正向扫描日志文件、对UNDO队列中的事务进行UNDO处理、对REDO队列中的事务进行REDO处理D．正向扫描日志文件、对REDO队列中的事务进行REDO处理、对UNDO队列中的事务进行UNDO处理
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.
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.
The UNDO_RETENTION parameter in your database is set to 1000 and undo retention is not guaranteed. Which statement regarding retention of undo data is correct？（）A、Undo data becomes obsolete after 1，000 seconds.B、Undo data gets refreshed after every 1，000 seconds.C、Undo data will be stored permanently after 1，000 seconds.D、Committed undo data would be retained for 1，000 seconds if free undo space is available.E、Undo data will be retained in the UNDO tablespace for 1，000 seconds，then it gets moved to the TEMPORARY tablespace to provide read consistency.
Fireworks中，如果由于操作失误后想撤消所进行的操作命令，可以执行的操作有：（）A、单击UNDO图标撤消失误操作B、使用历史面板撤消失误操作C、按键盘的Ctrl+Z键撤消失误操作D、选择Edit菜单中的Undo命令
单选题Users in your PROD database complain about the slow response of the transactions. While investigating the reason， you find that the transactions are waiting for the undo segments to be available， and undo retention has been set to zero. What would you do to overcome this problem？（）Aincrease the undo retentionBcreate more undo segmentsCcreate another undo tablespaceDincrease the size of the undo tablespace
单选题What is true if you want to switch undo tablespaces from the current one， called UNDO1， to a new one called UNDO2？（）AIt is NOT possible to switch unless no active transaction exist in UNDO1. BIt is possible to switch to UNDO2； but current active transactions will abort. CIt is possible to switch to UNDO2； current active transactions will be automatically migrated to UNDO2. DIt is possible to switch to UNDO2； only current active transactions will continue to execute inside UNDO1.
多选题You require the Oracle server to manage the undo segments and space among various active sessions automatically. You created an undo tablespace， UNDO_TBS1， in your database. Which two additional steps would you perform to achieve this？（）ASet the UNDO_RETENTION parameter to 900 or more.BCreate an initial undo segment in the undo tablespace.CEnable the retention guarantee for the undo tablespace.DSet the UNDO_TABLESPACE parameter to UNDO_TBS1.ESet the UNDO_MANAGEMENT initialization parameter to AUTO.
多选题Fireworks中，如果由于操作失误后想撤消所进行的操作命令，可以执行的操作有：（）A单击UNDO图标撤消失误操作B使用历史面板撤消失误操作C按键盘的Ctrl+Z键撤消失误操作D选择Edit菜单中的Undo命令
判断题Undo命令可以撤消对视图的推拉、摇移的最后操作。（）A对B错