oracle11g ADG主备切换
1、主库
SQL> select name,open_mode,switchover_status from v$database;
NAME OPEN_MODE SWITCHOVER_STATUS
--------- -------------------- --------------------
PROD1 READ WRITE TO STANDBY
SQL> alter system switch logfile;
System altered.
SQL> alter system archive log current;
System altered.
SQL> alter database commit to switchover to physical standby with session shutdown;
Database altered.
SQL> shutdown abort
ORACLE instance shut down.
SQL> startup mount
ORACLE instance started.
Total System Global Area 849530880 bytes
Fixed Size 1348244 bytes
Variable Size 511708524 bytes
Database Buffers 331350016 bytes
Redo Buffers 5124096 bytes
Database mounted.
SQL> select switchover_status from v$database;
SWITCHOVER_STATUS
--------------------
RECOVERY NEEDED
SQL> alter database open;
Database altered.
SQL> select switchover_status from v$database;
SWITCHOVER_STATUS
--------------------
TO PRIMARY
2、备库
SQL> alter database commit to switchover to primary with session shutdown;
Database altered.
SQL> alter database open;
Database altered.
SQL> select name,open_mode,switchover_status from v$database;
NAME OPEN_MODE SWITCHOVER_STATUS
--------- -------------------- --------------------
PROD1 READ WRITE TO STANDBY
3、新备库（原主库）启用实时日志应用
SQL> alter database recover managed standby database using current logfile disconnect from session;
Database altered.
SQL> select name,open_mode,switchover_status from v$database;
NAME OPEN_MODE SWITCHOVER_STATUS
--------- -------------------- --------------------
PROD1 READ ONLY WITH APPLY NOT ALLOWED
参考链接：
https://blog.csdn.net/kadwf123/article/details/83092607
http://blog.chinaunix.net/uid-26313110-id-5748048.html