Resolving Gaps in DataGuard Physical Standby Using RMAN Incremental Backup

1.Defer log_archive_dest_state_2 in primary database

alter system set log_archive_dest_state_2='DEFER';

2.check Current_scn in primary and compare with Standby

SQL> select current_scn from v$database;
CURRENT_SCN
-----------
    3436343

3.alter database recover managed standby database cancel -->in standby
 rman target /

Recovery Manager: Release 11.2.0.2.0 - Production on Wed Oct 29 13:49:26 2014
Copyright (c) 1982, 2009, Oracle and/or its affiliates.  All rights reserved.
connected to target database: RMAN (DBID=1700890588)

RMAN>
run {
allocate channel c1 type disk format '/backup/%U.bkp';
backup incremental from scn 3436343 database;
}

4.Transfer the backup pieces to Standby location

5.Backup control file in Primary Database location and transfer to standby location

alter database create standby controlfile as '/tmp/control_standby.ctl';

6.Startup mount physical standby database with latest control file
alter database mount standby database;
rman target /
catalog start with '/backup/%U.bkp';

>recover database;

In Standby Database

SQL> alter database recover managed standby database disconnect from session;

Enable below command in primary

alter system set log_archive_dest_state_2='ENABLE'; 

Archive log GAP detection

Archive log GAP detection:

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;



Determining Which Log Files Were Not Received by the Standby Site.


SELECT LOCAL.THREAD#, LOCAL.SEQUENCE# FROM (SELECT THREAD#, SEQUENCE# FROM V$ARCHIVED_LOG WHERE DEST_ID=1) LOCAL WHERE LOCAL.SEQUENCE# NOT IN (SELECT SEQUENCE# FROM V$ARCHIVED_LOG WHERE DEST_ID=2 AND THREAD# = LOCAL.THREAD#);

Archive log difference:

ALTER SESSION SET NLS_DATE_FORMAT = 'DD-MON-YYYY HH24:MI:SS';

 SELECT a.thread#, b. last_seq, a.applied_seq, a. last_app_timestamp, b.last_seq-a.applied_seq ARC_DIFF FROM (SELECT thread#, MAX(sequence#) applied_seq, MAX(next_time) last_app_timestamp FROM gv$archived_log WHERE applied = 'YES' GROUP BY thread#) a, (SELECT thread#, MAX (sequence#) last_seq FROM gv$archived_log GROUP BY thread#) b WHERE a.thread# = b.thread#;


set lines 200
col name format a40
col value format a20
 select * from v$dataguard_stats;


  set lines 200
  col type format a30
  col ITEM format a20
  col comments format a20
  select * from v$recovery_progress;
 
 
  SET PAGESIZE 9999
  col day format a15
  SELECT A.*, Round(A.Count#*B.AVG#/1024/1024) Daily_Avg_Mb FROM(SELECT To_Char(First_Time,'YYYY-MM-DD') DAY, Count(1) Count#, Min(RECID) Min#, Max(RECID) Max# FROM gv$log_history GROUP BY To_Char(First_Time,'YYYY-MM-DD') ORDER BY 1 DESC) A,(SELECT Avg(BYTES) AVG#, Count(1) Count#, Max(BYTES) Max_Bytes, Min(BYTES) Min_Bytes FROM gv$log ) B;



Check MRP Rate:

set linesize 400
col Values for a65
col Recover_start for a21
select to_char(START_TIME,'dd.mm.yyyy hh24:mi:ss') "Recover_start",to_char(item)||' = '||to_char(sofar)||' '||to_char(units)||' '|| to_char(TIMESTAMP,'dd.mm.yyyy hh24:mi') "Values" from v$recovery_progress where start_time=(select max(start_time) from v$recovery_progress);


Delete Archive log in standby location:

#!/usr/bin/ksh
ARCH_DIR=/archive/orcl
#take the log number to be applied
LogNo=`tail -30000 /oracle/app/oracle/product/10.2.0/admin/orcl/bdump/alert* | grep "Media Recovery Log" | cut -d " " -f 4 | cut -d "_" -f 5 | tail -1 `
echo "Oracle applied LogNo is $LogNo"
#extract 10
let SecLogNo=${LogNo}-10
echo "new backlog log No: $SecLogNo"
#delete small numbers from this in arch dir
cd $ARCH_DIR
for i in `ls *.arc`
do
Newi=`echo $i | cut -d "_" -f 4`
if [ $Newi -lt $SecLogNo ] ; then
echo "$i to be deleted..."
rm $i
fi
done