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1.启动例程

conn sys/sys as sysdbastartup nomount

2.nomount 状态转为mount状态

alter database mount;alter database open;

3.启动例程并装载数据库

startup mount

4.启动例程装载并打开数据库

startup open

5.以受限模式打开数据库

startup restrict

6.以只读模式打开数据库

conn sys/sys as sysdbashutdown immediatestartup mountalter database open read only;update scott.emp set sal=1000 where empno=70;

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