How To Check Oracle Physical Standby is in Sync with the Primary or Not?

set pages 1000
set lines 120
column DEST_NAME format a20
column DESTINATION format a35
column ARCHIVER format a10
column TARGET format a15
column status format a10
column error format a15
select DEST_ID,DEST_NAME,DESTINATION,TARGET,STATUS,ERROR from v$archive_dest
where DESTINATION is NOT NULL

At Physical Standby

SELECT ARCH.THREAD# "Thread", ARCH.SEQUENCE# "Last Sequence Received", APPL.SEQUENCE# "Last Sequence Applied", (ARCH.SEQUENCE# - APPL.SEQUENCE#) "Difference"
FROM
(SELECT THREAD# ,SEQUENCE# FROM V$ARCHIVED_LOG WHERE (THREAD#,FIRST_TIME ) IN (SELECT THREAD#,MAX(FIRST_TIME) FROM V$ARCHIVED_LOG GROUP BY THREAD#)) ARCH,
(SELECT THREAD# ,SEQUENCE# FROM V$LOG_HISTORY WHERE (THREAD#,FIRST_TIME ) IN (SELECT THREAD#,MAX(FIRST_TIME) FROM V$LOG_HISTORY GROUP BY THREAD#)) APPL
WHERE
ARCH.THREAD# = APPL.THREAD#
ORDER BY 1



SELECT THREAD#, LOW_SEQUENCE#, HIGH_SEQUENCE# FROM V$ARCHIVE_GAP



select process,status,sequence# from v$managed_standby

Compare the output of the query its should be equal .