Finding the Archived Redo Logs (SAP Library - Database Administration (Oracle) with SAPDBA)

Finding the Archived Redo Logs

Select Find archive files to locate the archived redo log files. The summary BRARCHIVE log ( arch<DBSID>.log ) is scanned for valid backups of the redo log files required to recover the damaged data files. If the backup was performed with an external backup program, SAPDBA attempts to establish a link to that backup program and find the archived redo logs in this manner. The following menu items are displayed:

	Find archive files
a	- Specify first archive file to be found / restored
S	- Start finding archive files
b	- Show the list of archive files
q	- Return

Determining the Start Point for Restoring Logs

Select Specify first archive file to be found / restored.

SAPDBA displays the following log sequence numbers for each instance (thread):

The fixed number in the BRBACKUP backup used
(if no backup was restored, a value is determined from V$RECOVER_FILE and V$RECOVERY_LOG)

The number of the first offline redo log required (compare ORACLE: V$RECOVERY_LOG)

The number of the last (online) redo log required

The number SAPDBA suggests

These numbers will normally tally. If necessary, you can change the log sequence number of the first archive redo log file for restoring.

a	Select instance and change current first required log
q	Return

The log sequence number proposed by SAPDBA should only be changed in exceptional cases and by an experienced database administrator. Normally, finding the archive files can be started directly with the menu option S described below.

Start Finding the Archived Redo Logs

You must select menu item Start finding archive files so that SAPDBA can make available the archived redo log files and offline redo log files belonging to the lost data files. To find the archived redo log files, SAPDBA uses the BRARCHIVE summary log; to find the offline redo logs, it searches the directory where ORACLE archives its online redo log files.

If you used an external backup program for the backup, SAPDBA attempts to obtain the appropriate information from that program. You are prompted to enter the required parameter file. SAPDBA automatically suggests the parameter file in the BRARCHIVE profile BRARCHIVE ( init<DBSID>.sap ).

Any gaps in the archived redo logs are displayed. If the sequence of the redo log files required for recovery is interrupted, recovery using the SAPDBA function Check (and repair) database is impossible. A partial recovery with the SAPDBA function Restore/Recovery or with ORACLE tools is possible, but only with loss of data.

Display Functions for the Archived Redo Logs

Select the option Show the list of archive files to display the list of archived redo logs for the respective instance (that is, the logs beginning with the determined log sequence number) that are required for the recovery process. SAPDBA highlights any gaps in the redo log sequence.

Select Return to continue with the recovery process. The function Find archive files is assigned the status finished when the process is complete.

You must get offline redo log files of other instances which were not found from the archiving directories and store them manually or with BRARCHIVE in the local archiving directory. SAPDBA does not perform this action automatically.