--1、主、备库查看当前日志状况

SELECT SEQUENCE#,STATUS FROM V$LOG;

--2、备库查看RFS接收日志和MRP应用日志同步主库情况

SELECT PROCESS, SEQUENCE#, STATUS, DELAY_MINS FROM V$MANAGED_STANDBY;

--3、查看备库是否和主库同步

SELECT SEQUENCE#,STATUS FROM V$LOG;

SELECT ARCHIVED_THREAD#,ARCHIVED_SEQ#,APPLIED_THREAD#,APPLIED_SEQ# FROM V$ARCHIVE_DEST_STATUS;

--4、备库查看已经归档的REDO

SELECT REGISTRAR,CREATOR,THREAD#,APPLIED,SEQUENCE#,FIRST_CHANGE#,NEXT_CHANGE#, COMPLETION_TIME FROM V$ARCHIVED_LOG;

--5、备库查看已经应用的REDO

SELECT THREAD#,SEQUENCE#,FIRST_CHANGE#,NEXT_CHANGE# FROM V$LOG_HISTORY;

--6、主、备库查看是否有GAP

SELECT STATUS,GAP_STATUS FROM V$ARCHIVE_DEST_STATUS WHERE DEST_ID=2;

--7、备库查看GAP

SELECT * FROM V$ARCHIVE_GAP;

--8、主备库查询异常信息

SELECT T.STATUS,T.ERROR FROM V$ARCHIVE_DEST T;