OCP-1Z0-053-V12.02-679题

679.Which mode of database shutdown requires an instance recovery at the time of the next database

startup?

A.ABORT

B.NORMAL

C.IMMEDIATE

D.TRANSACTIONAL

Answer: A



答案解析：





The possible SHUTDOWN statements are:

SHUTDOWN ABORT

This mode is intended for emergency situations, such as when no other form of shutdown is successful.

This mode of shutdown is the fastest. However, a subsequent open of this database may take substantially longer

because instance recovery must be performed to make the data files consistent.

Note:
Because SHUTDOWN ABORT does not checkpoint the open data files, instance recovery is necessary before the database can reopen.

The other shutdown modes do not require instance recovery before the database can reopen.
因为shutdown abort不会生成检查点，所以再次打开数据库时要进行实例恢复。

SHUTDOWN IMMEDIATE

This mode is typically the fastest next to SHUTDOWN ABORT.
Oracle Database terminates any executing SQL statements and disconnects users.

Active transactions are terminated and uncommitted changes are rolled back.

SHUTDOWN TRANSACTIONAL

This mode prevents users from starting new transactions, but waits for all current transactions to complete before shutting down.

This mode can take a significant amount of time depending on the nature of the current transactions.

SHUTDOWN NORMAL

This is the default mode of shutdown. The database waits for all connected users to disconnect before shutting down.

官网参考：http://docs.oracle.com/cd/E11882_01/server.112/e40540/startup.htm#CNCPT955