You import backups of the database instance and recover the database status that they contain.

To recover the database instance completely, you first import the most up-to-date complete data backup. If you have created one or more incremental data backups after the complete data backup, you have to import them as well. To find out which data backup is the most up-to-date and which incremental data backups were made after it, look in the backup history (see backup_history_open).

After the data backup(s) have been imported, the system will display which log page to start importing the log backups with. You can also find this information in the backup history. On the basis of this information, select the first log backup to be imported. Then import the other log backups in chronological order.

You can look in the restart information to determine up to which log page you need to import the log backups. The system displays which log pages are still in the log area (i.e. beginning with which number) and thus can be restored by the system from that location (see db_restartinfo).

The backups to be imported must, in their entirety, comprise all the contents of the database without any gaps. The database system can only automatically recover the last log entries still in the log area if the log volumes are still intact.

If the log volumes still contain all the log entries since the last data backup import, it is enough to restart the database instance after importing the data backup(s) (see db_restart). The system then imports the content of the log area.

If you need to import more log backups after the data backup(s), the database system recognizes the page starting from which the missing content can be imported from the log area. The log backup import terminates at this point, the system recovers the remaining log pages from the log area and automatically transfers the database instance to the ONLINE operational state.

You can import both data backups that were created sequentially and data backups that were created on more than one data carrier in parallel into the database system.

Import data backups with the recover_start DBM command as well as the first log backup to be imported. You have to import all succeeding log backups with the continuation command recover_replace (after return value -8020, see Database Manager CLI Tutorial, Restoring the Database Instance).

When you set up a standby instance, you have to import all succeeding log backups with recover_start (after return value -7075, see Database Manager CLI Tutorial, Setting Up and Updating Standby Instances).

It is possible to recover the database instance only as far as a certain consistent state before a database or hard disk error occurred. When importing log backups, you can use an option to specify the point in time up to which the system imports the entries from the log backups or from the log area (as the case may be).

If you used a third-party backup tool to make these backups, use that tool to import the backups. To do so, determine the backup ID of the required backup first (see backup_ext_ids_get and backup_ext_ids_list). The Database Manager uses this ID to identify the backup that is to be imported.

The reply to the recover_start DBM command displays information about the import of the backup. However, this information is only displayed when the backup has been imported completely, or if the backup was interrupted. This command may therefore take a long time to execute.

You can display the ongoing status of the restore operation with the DBM command recover_state.

If it is clear from the message number that the restore was interrupted and not finished, you must continue the session with the continuation command (recover_replace) or terminate it with (recover_cancel).

If the automatic log backup was activated before the recovery was started, it is not reactivated automatically after the recovery. To reactivate the log backup function, execute DBM command autolog_on.

If you updated the software after the database state that the recovery takes you back to, you need to reload the system tables to adjust them to the new software version (see load_systab).