052-007題解析

 

7.

You have issued a SHUTDOWN ABORT command to bring down your database instance. Consider

the steps that will be performed later when you open the database:

1: SGA is allocated.

2: Control file is read.

3: Redo log files are read.

4: Instance recovery is started.

5: Background processes are started.

6: Data files are checked for consistency.

7: Server parameter file or the initialization parameter file is read.

Which option has the correct order in which these steps occur?

A.7, 1, 5, 2, 3, 6, 4

B.1, 2, 3,7, 5, 6, 4

C.7, 1, 4, 5, 2, 3, 6

D.1, 7, 5, 4, 2, 3, 6

Answer: A

 

答案解析：

shutdown abort後，再startup，需要用到smon進行例項恢復。

在nomount階段，讀取初始化引數，分配SGA，後臺程式啟動

在mount階段，讀取控制檔案和聯機日誌檔案，檢視需要開啟哪些資料檔案

在open階段，根據控制檔案內容找到資料檔案，並開啟，因為是abort關閉的資料庫，則在open時需要檢查資料庫，資料庫檔案以及資料檔案頭部的scn號是否一致，如果不一致，SMON程式進行例項恢復。