几种不同oracle数据库启动方式的对比，及启动状态的切换、查询

几种不同oracle数据库启动方式的对比，及启动状态的切换、查询

说明：几种不同oracle数据库启动方式的对比，及启动状态的切换、查询

1 状态查询

启动状态	SQL语句	结果
nomount	select status from v$instance;	STARTED
select open_mode from v$database;	ERROR at line 1: ORA-01507: database not mounted
mount	select status from v$instance;	MOUNTED
select open_mode from v$database;	MOUNTED
open	select status from v$instance;	OPEN
select open_mode from v$database;	READ WRITE 或者 READ ONLY

2 实验过程
SQL> startup nomount;
Oracle instance
started.
 
Total System Global Area  125829120 bytes
Fixed Size                  1247684 bytes
Variable Size              92276284 bytes
Database Buffers           25165824 bytes
Redo Buffers                7139328 bytes
 
SQL> select status from v$instance;
 
STATUS
------------
STARTED
 
SQL> select open_mode from v$database;
select open_mode from v$database
*
ERROR at line 1:
ORA-01507: database not mounted
 
SQL> alter database mount;
 
Database altered.
 
SQL> select status from v$instance;
 
STATUS
------------
MOUNTED
 
SQL> select open_mode from v$database;
 
OPEN_MODE
----------
MOUNTED
 
SQL> alter database open;
 
Database altered.
 
SQL> select status from v$instance;
 
STATUS
------------
OPEN
 
SQL> select open_mode from v$database;
 
OPEN_MODE
----------
90ca
READ WRITE