Steps to recover Standby database from a missing archivelog

A Physical Standby database relies on continuous application of archivelogs from a Primary Database to be in synch with it. In Oracle Database versions prior to 10g in the event of an archivelog gone missing or corrupt you had to rebuild the standby database from scratch.

In 10g you can use an incremental backup from SCN and recover the standby using the same to compensate for the missing archivelogs as shown below

Step 1: On the standby database check the current scn.

STDBY> set numwidth 30;
STDBY> select current_scn from v$database;

CURRENT_SCN
-----------
123456789

Step 2: On the primary database create the needed incremental backup from the above SCN

C:\Documents and Settings\frego>rman target /

RMAN> {
allocate channel c1 type disk;
BACKUP INCREMENTAL FROM SCN 123456789 DATABASE
FORMAT /tmp/incr_bkp/incr_bkp_%U';
}

Step 3: Cancel managed recovery at the standby database

STDBY>alter database recover managed standby database cancel;
Media recovery complete.

scp the backup files to standby server to /tmp/incr_bkp folder.

Step 4: Catalog the Incremental Backup Files at the Standby Database

/tmp/incr_bkp > rman target /

RMAN> CATALOG START WITH '/tmp/incr_bkp/';
searching for all files that match the pattern /tmp/incr_bkp/

List of Files Unknown to the Database
=====================================
......

Do you really want to catalog the above files (enter YES or NO)? YES
cataloging files...
cataloging done


Step 5: Apply the Incremental Backup to the Standby Database

RMAN> RECOVER DATABASE NOREDO;

Step 6: Put the standby database back to managed recovery mode.

STDBY>> recover managed standby database disconnect;
Media recovery complete.

From the alert.log you will notice that the standby database is still looking for the old log files


*************************************************
FAL[client]: Failed to request gap sequence
GAP - thread 1 sequence ....
**************************************************

This is because the controlfile has not been updated.
Hence the standby controlfile has to be recreated

Step 7: On the primary create new standby controlfile

PRIM>alter database create standby controlfile as ‘/tmp/incr_bkp/standby01.ctl’;
System altered.

Step 8: At Standby .. Replace standby controlfile at all location as shown by controle_files parameter.

Copy the standby control file to the standby site. Shutdown the stanby database and replace the stanby controlfiles and restart the standby database in managed recovery mode...