Gaps in Oracle Dataguard Standby

Question

Hello,
The system is a Logical Standby Dataguard.
With the following query it is possible to see that there are gaps:
SQL> set numformat 99999999999
SQL> set linesize 2000
SQL> set pagesize 20000
SQL> select thread# trd, sequence#,
2 first_change#, next_change#,
3 dict_begin beg, dict_end end,
4 to_char(timestamp, 'DD-MON-YYYY HH24:MI:SS') timestamp,
5 (case when l.next_change# < p.read_scn then 'YES'
6 when l.first_change# < p.applied_scn then 'CURRENT'
7 else 'NO' end) applied
8 from dba_logstdby_log l, dba_logstdby_progress p
9 order by thread#, first_change#;
1 614 18542918309 18542918429 NO NO 04-DEC-2009 09:31:11 YES
1 633 18543602669 18543836687 NO NO 04-DEC-2009 09:31:10 YES
1 637 18543836687 18544028244 NO NO 04-DEC-2009 09:31:10 YES
1 12832 203846572934 203846572944 NO NO 22-DEC-2009 09:31:10 YES
Although all of them are APPLIED, and it is still receiving and applying the redo, it seems like there are some gaps.
How can I check that the Standby is totally synchronized? How can I check if the Standby has still those archive logs that haven't been applied?
Thanks in advance.

Answer 1

There are errors in the alert of the Primary on the 4th of Dec. and it seems like the Primary had problems trying to do the archive in the Standby:
Error 1034 received logging on to the standby
Errors in file /opt/oracle/diag/rdbms/db_s2/DB1/trace/DB1_arc5_15720.trc:
ORA-01034: ORACLE not available
FAL[server, ARC5]: FAL archive failed, see trace file.
Errors in file /opt/oracle/diag/rdbms/db_s2/DB1/trace/DB1_arc5_15720.trc:
ORA-16055: FAL request rejected
ARCH: FAL archive failed. Archiver continuing
ORACLE Instance DB1 - Archival Error. Archiver continuing.
The thing is that I don't know if those archive logs where sent or not to the Standby and if the Standby applied them or not.
By the following query, it seems like there are some archive logs that weren't applied, but the strange thing is that the Standby is still working and applying and that there are archive logs from today which have been received and applied, and as far as I know, the DG stops applying if there are gaps...
1 633 18543602669 18543836687 NO NO 04-DEC-2009 09:31:10 YES
1 637 18543836687 18544028244 NO NO 04-DEC-2009 09:31:10 YES
1 12832 203846572934 203846572944 NO NO 22-DEC-2009 09:31:10 YES
...