10gr2上switchover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 ---------------- ---------- -------------------- PRIMARY READ 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 mounted ORACLE instance shut down. SQL> startup mount; ORACLE instance started. Total System Global Area 390070272 bytes Fixed Size 2021024 bytes Variable Size 150997344 bytes Database Buffers 234881024 bytes Redo Buffers 2170880 bytes Database 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$database; NAME DATABASE_ROLE OPEN_MODE SWITCHOVER_STATUS --------- ---------------- ---------- -------------------- ORCLDB PHYSICAL STANDBY MOUNTED TO PRIMARY SQL> select switchover_status from v$database; SWITCHOVER_STATUS -------------------- TO PRIMARY SQL> 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; NAME DATABASE_ROLE OPEN_MODE SWITCHOVER_STATUS --------- ---------------- ---------- -------------------- ORCLDB PRIMARY READ 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$archived_log; REGISTR THREAD# SEQUENCE# FIRST_CHANGE# NEXT_CHANGE# ------- ------- ---------- ------------- ------------ FGRD FGRD 29 586174 586196 dg2上经过几次日志切换， SQL> select * from v$log; GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- --------- 1 1 36 52428800 1 NO CURRENT 586469 05-JAN-14 2 1 34 52428800 1 YES INACTIVE 586464 05-JAN-14 3 1 35 52428800 1 YES INACTIVE 586467 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# ------- ------- ---------- ------------- ------------ RFS ARCH 34 586464 586467 RFS ARCH 35 586467 586469

以上的主备切换过程就已经顺利进行完成。

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