Oracle Dataguard – Views to check the Status & Apply Lags

V$DATAGUARD_STATS

SELECT NAME, VALUE, TIME_COMPUTED 
FROM V$DATAGUARD_STATS 
WHERE NAME IN ('apply lag', 'transport lag’);

V$MANAGED_STANDBY

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

V$ARCHIVE_DEST_STATUS

SELECT DEST_ID, STATUS, GAP_STATUS, ERROR 
FROM V$ARCHIVE_DEST_STATUS 
WHERE TYPE = 'PHYSICAL' AND GAP_STATUS != 'NO GAP';