DataGuard related

select a.thread#, a.seq max_applied_seq, b.seq max_archived_seq
  from (select thread#, max(sequence#) seq
          from v$log_history
         group by thread#) a,
       (select thread#, max(sequence#) seq
          from v$archived_log
         group by thread#) b
 where a.thread# = b.thread#;