10g r2上switch over主备库的过程演示

当前状态是dg1为主库，备库为dg2先检查主备库状态：dg1SQLselectname,database_role,OPEN_MODE,SWITCHOVER_STATUSfromv$database;DATABASE_ROLEOPEN_MODESWITCHO

当前状态是dg1为主库，备库为dg2
先检查主备库状态：
dg1

SQL> select name,database_role,OPEN_MODE,SWITCHOVER_STATUS from v$database;DATABASE_ROLE OPEN_MODE SWITCHOVER_STATUS—————- ———- ——————–PRIMARYREAD WRITE SESSIONS ACTIVE

dg2

SQL> select database_role,OPEN_MODE,SWITCHOVER_STATUS from v$database;DATABASE_ROLE OPEN_MODE SWITCHOVER_STATUS—————- ———- ——————–

PHYSICAL STANDBY MOUNTED NOT ALLOWED

现在dg1（当前主库）上操作以下步骤：

SQL> alter database commit to switchover to physical standby with session shutdown;Database altered.SQL> shutdown immediate;ORA-01507: database not mountedORACLE instance shut down.SQL> startup mount;ORACLE instance started.Total System Global Area 390070272 bytesFixed Size2021024 bytesVariable Size150997344 bytesDatabase Buffers234881024 bytesRedo Buffers2170880 bytesDatabase mounted.SQL> select switchover_status from v$database;SWITCHOVER_STATUS——————–TO PRIMARY

现在dg2（当前备库）上操作以下步骤：

SQL> select name,database_role,OPEN_MODE,SWITCHOVER_STATUS from v$database;NAMEDATABASE_ROLE OPEN_MODE SWITCHOVER_STATUS——— —————- ———- ——————–ORCLDB PHYSICAL STANDBY MOUNTED TO PRIMARYSQL> select switchover_status from v$database;SWITCHOVER_STATUS——————–TO PRIMARYSQL> alter database commit to switchover to primary;Database altered.SQL> alter database open;Database altered.SQL> select name,database_role,OPEN_MODE,SWITCHOVER_STATUS from v$database;NAMEDATABASE_ROLE OPEN_MODE SWITCHOVER_STATUS——— —————- ———- ——————–ORCLDB PRIMARYREAD WRITE SESSIONS ACTIVE

以上的操作已经完成了主备的切换，现在dg2为主库，dg1为备库，接下来我们在现在的主库dg2上做几次日志变化，，看dg1能否同步过来。
dg1上看已经归档的日志：

SQL> select registrar,creator thread#,sequence#,first_change#,next_change# from v$archived_log;REGISTR THREAD# SEQUENCE# FIRST_CHANGE# NEXT_CHANGE#——- ——- ———- ————- ————FGRD FGRD29586174586196dg2上经过几次日志切换，SQL> select * from v$log;GROUP# THREAD# SEQUENCE#BYTES MEMBERS ARC STATUSFIRST_CHANGE# FIRST_TIM———- ———- ———- ———- ———- — —————- ————- ———1136 524288001 NO CURRENT586469 05-JAN-142134 524288001 YES INACTIVE586464 05-JAN-143135 524288001 YES INACTIVE586467 05-JAN-14

可以看出现在日志已经到了36，那么我们在dg1上应用日志，应该会应用到日志35；
以下操作验证：

SQL> alter database recover managed standby database disconnect from session;Database altered.SQL> select registrar,creator thread#,sequence#,first_change#,next_change# from v$archived_log;REGISTR THREAD# SEQUENCE# FIRST_CHANGE# NEXT_CHANGE#——- ——- ———- ————- ————RFSARCH34586464586467RFSARCH35586467586469

以上的主备切换过程就已经顺利进行完成。

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