[单选]

Your production database is running in archivelog mode and you are using recovery manager （RMAN） with recovery catalog to perform the database backup at regular intervals. When you attempt to restart the database instance after a regular maintenance task on Sunday， the database fails to open displaying the message that the data file belonging to the users tablespace are corrupted.  
The steps to recover the damaged data files are follows：  
1. Mount the database 
2. Open the database 
3. Recover the data file 
4. Restore the data file 
5. Make the data file offline 
6. Make the data file online  
Which option identifies the correct sequence that you must use to recover the data files？（）

企业界经营管理理论知识和实践经验的积累同施工技术管理工作一样具备许多年理论知识和实践经验积累。 某线路送有功10MW，送无功5MvAr，模拟C相接地短路，零序方向继电器的动作情况是：通入A相负荷电流，继电器动作；通入B相负荷电流，继电器不动作；通入C相负荷电流，继电器动作，该继电器的接线（）。 正确。 B不正确。 不能判断。 Examine the details of the Top 5 Timed Events in the following Automatic Workloads Repository (AWR)report:What are three possible causes for the latch-related wait events?（） The size of the shared pool is too small.。 Cursors are not being shared.。 A large number COMMITS are being performed.。 There are frequent logons and logoffs.。 The buffers are being read into the buffer cache, but some other session is changing the buffers.。 At design time, you create a query record group for the LOV associated with the HOTEL text item in a form module for the Travel Planner Application. When is the record group populated?（） When the user navigates to the HOTEL item. 。 When the form module successfully compiles. 。 After Form Builder validates the SELECT statement and dismisses the New Record Group dialog box. 。 When the user enters data in the HOTEL item, and the Validate from List property for the HOTEL item is set to YES.&e。 用人单位可以按照国家规定的本单位职工工资总额的比例缴纳基本养老保险费，记入基本养老保险统筹基金。

Your production database is running in archivelog mode and you are using recovery manager （RMAN） with recovery catalog to perform the database backup at regular intervals. When you attempt to restart the database instance after a regular maintenance task on Sunday， the database fails to open displaying the message that the data file belonging to the users tablespace are corrupted.  
The steps to recover the damaged data files are follows：  
1. Mount the database 
2. Open the database 
3. Recover the data file 
4. Restore the data file 
5. Make the data file offline 
6. Make the data file online  
Which option identifies the correct sequence that you must use to recover the data files？（）