Overwrite Mode for the Log Area 

One possible log setting that you can make is to specify the overwrite mode for the log area. This overwrite mode controls whether the log area can be overwritten or not without backing up the log entries.

Normal Log Backups

By default, the log area can be overwritten only if the appropriate log entries have been backed up, which is why you must make log backups at regular intervals (see Backup Strategy).

The log entries of the log area and the log backups are then available if you need to restore the database. As long as they are complete, you can use the data backup, log backups and the log entries in the log area to recover the database up to a chosen point in time.

If you change this default, and then reactivate it, you must then make a complete data backup.

Overwriting the Log Area Without a Log Backup

The log area is overwritten cyclically, and you do not need to back up the log entries.

The log backup history is interrupted. Only the log entries of the log area are available if you need to recover the database. This usually means that you cannot recover your database instance up to the last COMMIT before the crash, or to any other time; instead, you can recover it only to the state it had at the time of the last data backup.

You can only recover the database to a time of your choice if all the log entries written after the data backup exist in the log area (which means that the log area has not been overwritten since the data backup).

Procedure

Use the Database Manager to set the overwrite mode to your requirements.