In a log backup, the contents of the log area are copied to version files or backed up using an external backup tool.
A version file is generated for each log segment of the log area.
The space originally taken up by the backed up log area becomes free again after the log backup.
The following log backup options are supported for the database system SAP DB:
·
In the case
of a restore, a data backup
alone is not enough to restore the current state of the database instance
up to a certain point in time (for example, the time just before the disk
error occurred).
To restore the current state, both the data backup and the log entries that
were written after the data backup must be imported into the database
system.
· If new log entries cannot be written because there is not enough storage space in the log area, the database stops.
For these reasons, it is necessary to back up the log entries at regular intervals.
See also: Backing Up