（566）You have lost all your SYSTEM tablespace datafiles(system_01.dbf and system_02.dbf) and the database has crashed.

What would be the appropriate order of operations to correct the situation?

a. Mount the database with the startup mount command.

b. Take the SYSTEM datafile offline with the alter database command.

c. Restore the SYSTEM_01.dbf datafile from backup media with the required archived redo logs.

d. Restore all SYSTEM tablespace-related datafiles from backup media.

e. Issue the recover tablespace SYSTEM command.

f. Issue the recover datafile SYSTEM_01.dbf command.

g. Open the database with the alter database open command.

h. Open the database with the alter database open resetlogs command.

A. a,c,f,g

B. b,d,e,h

C. a,b,c,f,g

D. d,a,e,g

E. b,c,f,e,g

答案：（D）

解析：

如果某个数据文件丢失或损坏，且该文件属于SYSTEM或UNDO表空间，请执行以下任务：

1.实例可能会也可能不会自动关闭。如果未自动关闭，请使用SHUTDOWN ABORT关闭实例。

2.装载数据库。

3.还原并恢复缺失的数据文件。

4.打开数据库。

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Oracle 11G OCP 1Z0-053 566