如何查看数据库当前的状态？

如何查看数据库当前的状态

SQL> startup nomount
ORACLE instance started.

Total System Global Area  437327188 bytes
Fixed Size                   451924 bytes
Variable Size             134217728 bytes
Database Buffers          301989888 bytes
Redo Buffers                 667648 bytes
SQL> select status from v$instance;

STATUS
------------------------
STARTED

SQL> alter database mount
  2  /

Database altered.

SQL> select status from v$instance;

STATUS
------------
MOUNTED

SQL> alter database open;

Database altered.

SQL> select status from v$instance;

STATUS
------------
OPEN

查看当前数据库的读写性质

SQL>select open_mode from v$database

OPEN_MODE
------------
READ WRITE