Determining Which Logs Have Not Been Received by the Standby Site

Each archive destination has a destination ID assigned to it. You can query the DEST_ID column in the V$ARCHIVE_DEST fixed view to find out your destination ID. You can then use this destination ID in a query on the primary database to discover logs that have not been sent to a particular standby site.

For example, assume the current local archive destination ID on your primary database is 1, and the destination ID of one of your remote standby databases is 2. To find out which logs have not been received by this standby destination, issue the following query on the primary database:

SQL> SELECT LOCAL.THREAD#, LOCAL.SEQUENCE# FROM
2> (SELECT THREAD#, SEQUENCE# FROM V$ARCHIVED_LOG WHERE DEST_ID=1) LOCAL
3> WHERE
4> LOCAL.SEQUENCE# NOT IN
5> (SELECT SEQUENCE# FROM V$ARCHIVED_LOG WHERE DEST_ID=2 AND
6> THREAD# = LOCAL.THREAD#);

THREAD# SEQUENCE#
---------- ----------
1 12
1 13
1 14

The preceding example shows the logs that have not yet been received by standby destination 2.

regards,
rajeshkumar govindarajan

source and reference:
http://www-css.fnal.gov/dsg/external/oracle_dcm/9iv2/server.920/a96653/sbydb_manage_ps.htm#1005941

related topics:
Dyanamic performance views for managing standby database
Determine which Log Have Been Applied to the standby database