Actions after a Partial Recovery (SAP Library - Database Administration (Oracle) with SAPDBA)

Actions after a Partial Recovery

This section describes the measures that you should perform after a partial recovery with the case tapes below:

Case 1: Restore of a complete offline backup and subsequently opening the database, without performing a complete recovery of the database

Case 2: Restore of a complete online or offline backup and subsequent point in time recovery of the database (with ALTER DATABASE OPEN RESETLOGS)

Possible Problem Situations:

Situation A: The information about the last backups and volumes used in database tables SDBAH and SDBAD has been lost, because neither item is current in the database. As a result, during the next backup, BRBACKUP prompts you to mount volumes (based on the automatic volume management) that are logically free, but are physically locked.

Situation B: The current log sequence number was reset during a partial recovery.

To a smaller value in case 1
To the value 1 in case 2

BRARCHIVE does not find the newly written offline redo log files after the restore, because offline redo logs with these log sequence numbers have already been saved. The summary BRARCHIVE log arch<DBSID>.log still contains entries for successful archiving runs of these offline redo log files and, as a result, BRARCHIVE does not detect the new offline redo log files as files requiring archiving.

Solutions to the Problem Situations

Situation A: Using the detail BRBACKUP log, you can find out which volume was the last one used. Based on the information on the volume pool in initialization profile init<DBSID>.sap (parameter volume_backup ), you can determine which volume should be used for the next backup. Explicitly name this volume when you start the next backup:

brbackup -v <volume name1>[,<volume name2>,... ]

Situation B: Make sure the old offline redo log files in the archiving directory are renamed.

Case 1: The current log sequence number can be seen in the detail BRBACKUP log of the backup you used to restore the data. Find the line Current log sequence (message BR116I). Then change the log sequence number in the last line of the summary BRARCHIVE log arch<DBSID>.log , which starts with #ARCHIVE , to the value: <(determined current log sequence number) -1> .

Example: entry before:

#ARCHIVE. 86 /oracle/C11/saparch/C11arch_86 1995-04-18 15.55.55

Current log sequence number determined: 30

Entry must be changed to:

#ARCHIVE. 29 /oracle/C11/saparch/C11arch_86 1995-04-18 15.55.55

After the archiving, you should reset the changes in this line (note that new lines have been added).

Case 2: Change the log sequence number in the last line of the summary BRARCHIVE log arch<DBSID>.log , which starts with #ARCHIVE , to zero (0).

Example: entry before:

#ARCHIVE. 86 /oracle/C11/saparch/C11arch_86 1995-04-18 15.55.55

Entry must be changed to:

#ARCHIVE. 0 /oracle/C11/saparch/C11arch_86 1995-04-18 15.55.55

After the archiving, you should reset the changes in this line (note that new lines have been added).

BRARCHIVE automatically recognizes the resetting of log sequence numbers if the database is opened when BRARCHIVE is started. In this case, the actions described in situation B are not necessary.

In general (as after all recovery operations), offline redo log files that were restored from tape to disk should be deleted from the disk after the recovery.