backup_type
Identifies the default type of the database backup. This parameter is only used by BRBACKUP.
Default: offline
Possible values:
online : Database backup in online mode, in other words, with the database running.
online_cons : Database backup in online mode. As well as the database files, the
offline redo log files generated during the backup are copied to the same volume. You
then have a logically consistent dataset available. This backup of the offline redo log files
with BRBACKUP runs completely independently of other BRARCHIVE backups.
offline : Database backup in offline mode, in other words, the database is shut down
during backup. When you select this parameter, BRBACKUP checks that no SAP system
users are connected to the database. If an SAP System is active, the database is not
shut down and BRBACKUP terminates the process with an error message (message
number BR068E).
offline_force : Database backup in offline mode, in other words, the database is shut
down during backup. BRBACKUP always shuts down the database, even if the SAP
System is active.
offline_standby : Data backup of a standby database in offline mode; in other words,
the standby database is shut down during the backup. This backup mode is only relevant
for the disaster recovery configuration. See Standby Database Scenario.
online_split : The mirror disks are split and backed up while the database is running.
The tablespaces to be backed up are only placed in BACKUP status during the split. This
backup mode is only relevant for the ‘split mirror’ configuration. See: Split Mirror Disks
Backup.
offline_split : The database is only shut down for the mirror disks split. The backup
of the mirror disks can take place whilst the database is running. The R/3 System is
available during the entire split mirror backup. Restriction: No transactions can be carried
out during the short period of time that the database is shut down.
This backup mode is only relevant for the ‘split mirror’ configuration. See: Split Mirror
Disks Backup.
offline_stop: Database backup in offline mode without a consequent startup of the
database. After its backup the database can be transferred directly into the mount
standby status.
This type of backup is only relevant in the following case: The productive database is
saved and then takes over the role of a standby database. The backup itself becomes a
productive system. See: Standby Database Scenario:
Online Mode and Offline Mode
Online Mode
Purpose
You can perform an online backup with the database running - that is, the users can continue to
work normally. The management of database changes by the corresponding Oracle background
processes is not affected either.
Tablespace online backups are inconsistent. The database can only be made consistent in a
recovery if redo log entries from the period between BEGIN BACKUP and END BACKUP and
exist and can be imported.
Prerequisites
An online backup is made using operating system utilities (for example, under the control of the
SAP utility BRBACKUP). Because these utilities are not part of the database system, you must be
informed about the starting point of a backup. In this way, a unique restart point is defined from
which the recreation of all the files of a tablespace can be carried out in case of an error.
Procedure
The starting point of the backup is set using the command ALTER TABLESPACE
BEGIN BACKUP. The header of the tablespace files holds
information on the checkpoint and redo log files. When the next redo log file switch or
checkpoint occurs (normal database operations continue), the header information
remains unchanged.
Based on this mechanism, all the files of a tablespace are copied with uniform header
information specifying when the backup was started.
Once the backup of the tablespace is complete, the command ALTER TABLESPACE
END BACKUP ensures that the header information of the files is
updated.
Offline Mode
Purpose
After an offline backup of the complete database, you have a backup of the database that is
consistent. If you work with the database after the backup, the backup is consistent, but not up-to-
date. In this case, you have to recover the database after you restore the backup.
Prerequisites
The database is closed during an offline backup; because the database cannot be accessed you
cannot work with the R/3 System during an offline backup. However, the R/3 System does not
have to be shut down for an offline backup. If the RECONNECT mechanism is set in the SAP
start profiles, the connection to the R/3 System is remade after the database is restarted; this
means that the information in the buffers of the R/3 System is not lost.