Oracle 11g Data Guard之主备库切换（switchover不使用DG Broker）

--目前主库PROD3,备库AUX
--查看主备库日志传输情况
SYS@PROD3> select max(sequence#) from v$archived_log;

MAX(SEQUENCE#)
--------------
	    34
		
SYS@aux> select sequence#,applied from v$archived_log order by 1 desc;

 SEQUENCE# APPLIED
---------- ---------
	34 YES
	34 YES
	34 YES
	33 YES
	32 YES
	31 YES
	30 YES		
	
--查看主备库状态	
SYS@PROD3> select name,database_role,switchover_status from v$database;

NAME	  DATABASE_ROLE    SWITCHOVER_STATUS
--------- ---------------- --------------------
PROD3	  PRIMARY	   TO STANDBY

SYS@aux> select name,database_role,switchover_status from v$database;

NAME	  DATABASE_ROLE    SWITCHOVER_STATUS
--------- ---------------- --------------------
PROD3	  PHYSICAL STANDBY NOT ALLOWED

--先主库切换到备库
SYS@PROD3> alter database commit to switchover to physical standby with session shutdown;

Database altered.
--同时备库trace文件中节选
RFS[2]: Possible network disconnect with primary database


SYS@aux> select name,database_role,switchover_status from v$database;

NAME	  DATABASE_ROLE    SWITCHOVER_STATUS
--------- ---------------- --------------------
PROD3	  PHYSICAL STANDBY TO PRIMARY

--备库切换到主库
SYS@aux> alter database commit to switchover to primary;

Database altered.

SYS@aux> alter database open;

Database altered.

--启动备库进行恢复
SYS@PROD3> startup
ORACLE instance started.

Total System Global Area  958341120 bytes
Fixed Size		    1348972 bytes
Variable Size		  281021076 bytes
Database Buffers	  671088640 bytes
Redo Buffers		    4882432 bytes
Database mounted.
Database opened.

SYS@PROD3> select open_mode from v$database; 

OPEN_MODE
--------------------
READ ONLY

SYS@PROD3> select name,database_role,switchover_status from v$database;

NAME	  DATABASE_ROLE    SWITCHOVER_STATUS
--------- ---------------- --------------------
PROD3	  PHYSICAL STANDBY RECOVERY NEEDED

SYS@PROD3> alter database recover managed standby database disconnect from session;  

Database altered.

SYS@PROD3> select name,database_role,switchover_status from v$database;

NAME	  DATABASE_ROLE    SWITCHOVER_STATUS
--------- ---------------- --------------------
PROD3	  PHYSICAL STANDBY NOT ALLOWED

SYS@PROD3> select open_mode from v$database; 

OPEN_MODE
--------------------
READ ONLY WITH APPLY

--查看主库状态
SYS@aux> select open_mode from v$database; 

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

SQL> select name,database_role,switchover_status from v$database;

NAME	  DATABASE_ROLE    SWITCHOVER_STATUS
--------- ---------------- --------------------
PROD3	  PRIMARY	   TO STANDBY