查看主库状态:

select open_mode,protection_mode,database_role,switchover_status from v$database;

OPEN_MODE            PROTECTION_MODE             DATABASE_ROLE         SWITCHOVER_STATUS

-------------------- ----------------------------- ------------------------ ------------------------

READ WRITE           MAXIMUM PERFORMANCE      PRIMARY                      TO STANDBY

查看备库状态：

select open_mode,protection_mode,database_role,switchover_status from v$database;

OPEN_MODE                   PROTECTION_MODE             DATABASE_ROLE         SWITCHOVER_STATUS

------------------------- ----------------------------- ------------------------ ------------------------

READ ONLY WITH APPLY MAXIMUM PERFORMANCE      PHYSICAL STANDBY      NOT ALLOWED

检查主备两边的序号

select max(sequence#) from v$log;

备库执行，查看是否有数据未应用

select name,SEQUENCE#,APPLIED from v$archived_log order by sequence#;

select SEQUENCE#,FIRST_TIME,NEXT_TIME ,APPLIED from v$archived_log order by 1;