I have DR. Primary and Standby setup. The synch is not happening. How to investigate it?
See the query below if it is helpful.
Standby:
SQL> 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; 5
Thread Last Sequence Received Last Sequence Applied Difference
---------- ---------------------- --------------------- ----------
1 17802 17802 0
Primary:
SQL> SELECT THREAD# "Thread",SEQUENCE# "Last Sequence Generated"
FROM V$ARCHIVED_LOG WHERE (THREAD#,FIRST_TIME ) IN (SELECT THREAD#,MAX(FIRST_TIME) FROM V$ARCHIVED_LOG GROUP BY THREAD#) ORDER BY 1; 2
Thread Last Sequence Generated
---------- -----------------------
1 18258
1 18258