oracle的启动与关闭原理-oracle的启动阶段

案例1：如何知道当前数据库是处于哪个阶段

SQL> select instance_name,status from v$instance;

INSTANCE_NAME STATUS
-------------------------------- ------------------------
ORCL STARTED --nomount阶段

SQL> select instance_name,status from v$instance;

INSTANCE_NAME STATUS
---------------- ------------
ORCL MOUNTED --mount阶段

SQL> select instance_name,status from v$instance;

INSTANCE_NAME STATUS
---------------- ------------
ORCL OPEN --open阶段