switchover:
主库切换为备库：
SQL> select database_role ,switchover_status from v$database;

DATABASE_ROLE                    SWITCHOVER_STATUS
-------------------------------- ------------------------------------
PRIMARY                          SESSIONS ACTIVE

SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL STANDBY WITH SESSION SHUTDO
WN;

数据库已更改。

SQL>
SQL> select database_role ,switchover_status from v$database;
select database_role ,switchover_status from v$database
                                             *
ERROR 位于第 1 行:
ORA-01507: 未安装数据库

SQL> startup mount;
ORA-01081: 无法启动已在运行的 ORACLE --- 请首先关闭
SQL> shutdown immediate;
ORA-01507: 未安装数据库

ORACLE 例程已经关闭。
SQL> startup mount;
ORACLE 例程已经启动。

Total System Global Area  143727516 bytes
Fixed Size                   453532 bytes
Variable Size             109051904 bytes
Database Buffers           33554432 bytes
Redo Buffers                 667648 bytes
ORA-01666: ???????????

SQL> select database_role ,switchover_status from v$database;
select database_role ,switchover_status from v$database
                                             *
ERROR 位于第 1 行:
ORA-01507: ??????

SQL> select status from v$instance;

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

SQL> alter database mount standby database;

数据库已更改。

SQL> alter database recover managed standby database;

C:\>set or
ORACLE_SID=auxdb2

C:\>sqlplus "/ as sysdba"

SQL*Plus: Release 9.2.0.1.0 - Production on 星期日 5月 4 10:40:34 2008

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

连接到:
Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.1.0 - Production

SQL> spool d:\dg\2.txt
SQL>  select log_mode ,database_role,switchover_status,force_logging from v$data
base;

LOG_MODE                 DATABASE_ROLE
------------------------ --------------------------------
SWITCHOVER_STATUS                    FORCE_
------------------------------------ ------
ARCHIVELOG               PHYSICAL STANDBY
SESSIONS ACTIVE                      YES

SQL>  select process,client_process,sequence#,status from v$managed_standby;

PROCESS        CLIENT_PROCESS    SEQUENCE# STATUS
-------------- ---------------- ---------- ------------------------
ARCH           ARCH                      0 CONNECTED
ARCH           ARCH                      0 CONNECTED
RFS            N/A                       0 RECEIVING
MR(fg)         N/A                      45 WAIT_FOR_LOG

SQL> show parameter standby;

NAME                                 TYPE
------------------------------------ ----------------------
VALUE
------------------------------
standby_archive_dest                 string
D:\oracle\auxdb\standbyArch
standby_file_management              string
auto
SQL> spool off;

备库切换为主库：
SQL> show parameter fal

NAME                                 TYPE                                      
------------------------------------ ----------------------                    
VALUE                                                                          
------------------------------                                                 
fal_client                           string                                    
tstdb                                                                          
fal_server                           string                                    
auxdb2                                                                         

SQL> select switchover_status from v$database;

SWITCHOVER_STATUS                                                              
------------------------------------                                           
SESSIONS ACTIVE                                                                

SQL> select switchover_status,database_role from v$database;

SWITCHOVER_STATUS                    DATABASE_ROLE                             
------------------------------------ --------------------------------          
SESSIONS ACTIVE                      PHYSICAL STANDBY                          

SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY;

数据库已更改。

SQL> select status from v$instance;

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

SQL> alter database open;
alter database open
*
ERROR 位于第 1 行:
ORA-01507: ??????

SQL> startup mount;
ORA-01081: ????????? ORACLE --- ?????
SQL> shutdown immediate;
ORA-01507: ??????

ORACLE 例程已经关闭。
SQL> startup
ORACLE 例程已经启动。

Total System Global Area  143727516 bytes                                      
Fixed Size                   453532 bytes                                      
Variable Size             109051904 bytes                                      
Database Buffers           33554432 bytes                                      
Redo Buffers                 667648 bytes                                      
数据库装载完毕。
数据库已经打开。

SQL> select switchover_status,database_role from v$database;

SWITCHOVER_STATUS                    DATABASE_ROLE                             
------------------------------------ --------------------------------          
SESSIONS ACTIVE                      PRIMARY                                   

已选择139行。

SQL> select a.NAME, a.SEQUENCE#, a.APPLIED
  2    from v$archived_log a
  3   where a.SEQUENCE# > 41
  4   order by a.FIRST_CHANGE# desc;

已选择17行。

SQL> alter system switch logfile;

系统已更改。

SQL>  select a.NAME, a.SEQUENCE#, a.APPLIED
  2    from v$archived_log a
  3   where a.SEQUENCE# > 41
  4   order by a.FIRST_CHANGE# desc;

     
   
已选择19行。

SQL> show parameter standby;

NAME                                 TYPE                                      
------------------------------------ ----------------------                    
VALUE                                                                          
------------------------------                                                 
standby_archive_dest                 string                                    
e:\oracle                                                                      
standby_file_management              string                                    
auto                                                                           
SQL> spool off;