DR Sync check script

Select al.thrd "Thread", almax "Last Seq Generated", lhmax "Last Seq Applied"
from (select thread# thrd, max(sequence#) almax
from v$archived_log
where resetlogs_change#=(select resetlogs_change# from v$database)
group by thread#) al,
(select thread# thrd, max(sequence#) lhmax
from v$log_history
where first_time=(select max(first_time) from v$log_history)
group by thread#) lh
where al.thrd = lh.thrd;