Archive Log List Showing 0 At Standby, But Standby Is Completely In Sync With Primary! (Doc ID 2041137.1)
On a standby database:
########### 11gR2:
SQL> select GROUP#,STATUS from v$log;
GROUP# STATUS
---------- ----------------
1 CLEARING
2 CLEARING_CURRENT
3 CLEARING
8 CLEARING
5 CLEARING
6 CLEARING
7 CLEARING
4 CLEARING
################In 12cR1: Status is UNUSED
SQL> select GROUP#,STATUS from v$log;
GROUP# STATUS
---------- ----------------
1 UNUSED
2 UNUSED
3 UNUSED
8 UNUSED
5 UNUSED
6 UNUSED
7 UNUSED
4 UNUSED
The Bug 16091872 : V$LOG ON PSBY SHOWS ONE PER THREAD AS CURRENT======>>>>>>>>>>>>>>> has been fixed in the 12.1.0.2 version.
This fix makes user able to remove ORL on Standby, and ORL on Standby will not be updated as ORL on primary changes
SOLUTION
Do not use ARCHIVE LOG LIST on standby side.
Use the queries below to determine if the databases are in sync
Primary: SQL> select thread#, max(sequence#) "Last Primary Seq Generated"
from v$archived_log val, v$database vdb
where val.resetlogs_change# = vdb.resetlogs_change#
group by thread# order by 1;
PhyStdby:SQL> select thread#, max(sequence#) "Last Standby Seq Received"
from v$archived_log val, v$database vdb
where val.resetlogs_change# = vdb.resetlogs_change#
group by thread# order by 1;
PhyStdby:SQL>select thread#, max(sequence#) "Last Standby Seq Applied"
from v$archived_log val, v$database vdb
where val.resetlogs_change# = vdb.resetlogs_change#
and val.applied in ('YES','IN-MEMORY')
group by thread# order by 1;