在standby database上运行：

• Start databse as read only model.

SQL> startup mount;  
SQL> alter database open read only;

• Start real-time apply.

SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT FROM SESSION;

Database altered.

• show database status

SQL> select db_unique_name,database_role,open_mode from v$database; 

DB_UNIQUE_NAME      DATABASE_ROLE        OPEN_MODE
--------------     -----------------    --------------------
shenzhen_un         PHYSICAL STANDBY     READ ONLY WITH APPLY

• Stop Redo Apply.

SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;

Database altered.

• Check the Redo Apply service status.

SQL> SELECT THREAD#,SEQUENCE#,PROCESS,CLIENT_PROCESS,STATUS,BLOCKS FROM V$MANAGED_STANDBY;

• Check the status of the latest log sequence.

SQL> SELECT SEQUENCE#,APPLIED FROM V$ARCHIVED_LOG ORDER BY SEQUENCE#; 

• last archived sequence（can use also in primary）

SQL> SELECT MAX(SEQUENCE#) FROM V$ARCHIVED_LOG;

• last applied sequence

SQL> SELECT MAX(SEQUENCE#) FROM V$ARCHIVED_LOG WHERE APPLIED='YES';