ADG主备正常切换操作参考：RAC两节点->单机（11g)

1.主库准备

检查状态

SQL> select inst_id,database_role,OPEN_MODE from  gv$database;
 
   INST_ID DATABASE_ROLE    OPEN_MODE
---------- ---------------- --------------------
         2 PRIMARY          READ WRITE
         1 PRIMARY          READ WRITE
多租户：
SQL> show pdbs;

停掉一个实例：

[oracle@tyzfdb02 ~]$ srvctl stop instance -d tyzfdb -i tyzfdb2
 
SQL> select inst_id,database_role,OPEN_MODE from  gv$database;
 
   INST_ID DATABASE_ROLE    OPEN_MODE
---------- ---------------- --------------------
         1 PRIMARY          READ WRITE

2.备库准备

SQL> select inst_id,database_role,OPEN_MODE from  gv$database;
 
   INST_ID DATABASE_ROLE    OPEN_MODE
---------- ---------------- --------------------
         1 PHYSICAL STANDBY READ ONLY WITH APPLY
 
--取消备库日志应用： --可选
--SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;
 
--继续应用日志： --可选
--SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT;

3.主库切换日志：

主库切换日志,观察备库alert是否正常同步

SQL> alter system switch logfile;
 
System altered.
 
SQL> /
 
System altered.

4.备库确认同步正常

[oracle@adg trace]$ tail -f alert_tyzfdb.log 
Tue Jun 25 16:30:30 2023
Media Recovery Waiting for thread 2 sequence 122 (in transit)
Recovery of Online Redo Log: Thread 2 Group 12 Seq 122 Reading mem 0
  Mem# 0: +DATA/tyzfdb_adg/onlinelog/group_21.175.834665789
Tue Jun 25 16:30:30 2023
Archived Log entry 4890 added for thread 2 sequence 1629 ID 0x3545ffea dest 1:

上述信息Recovery of Online表示主备日志传输应用正常

5.主库切换

SQL> SELECT SWITCHOVER_STATUS FROM V$DATABASE;
SWITCHOVER_STATUS
--------------------
TO STANDBY
 
SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO STANDBY WITH SESSION SHUTDOWN;

6.备库切换

SQL> SELECT SWITCHOVER_STATUS FROM V$DATABASE;
 
SWITCHOVER_STATUS
--------------------
TO PRIMARY
 
SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY WITH SESSION SHUTDOWN;

SQL> ALTER DATABASE OPEN;

SQL> select name,SWITCHOVER_STATUS,database_role,OPEN_MODE from  gv$database;

7.继续处理主库变成备库：

SQL> shutdown immediate
ORA-01092: ORACLE instance terminated. Disconnection forced
SQL> exit

[oracle@tyzfdb01 ogg]$ sqlplus / as sysdba
SQL> startup mount
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT;--同步观察alert日志
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE cancel;
SQL> alter database open;
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT;
多租户：
SQL> show pdbs;
SQL> alter pluggable database xxx open;
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT;

8.主库启动节点2

[oracle@tyzfdb01 ~]$ srvctl start instance -d tyzfdb -i tyzfdb2
[oracle@tyzfdb01 ~]$ crsctl stat res -t

9.相关参考：

https://docs.oracle.com/en/database/oracle/oracle-database/19/sbydb/performing-oracle-data-guard-role-transitions.html#GUID-EEBC6DA6-E192-470E-8FC9-F507B004406E
https://mp.weixin.qq.com/s/p9ds8GKiQLKOpeJIO_g9xA
https://www.cnblogs.com/jyzhao/p/17184490.html
https://www.modb.pro/db/29798

##单机切换截图：