You can use this log setting to configure whether the database system overwrites the log area cyclically without first backing up the log entries.
Only switch on overwrite mode if it is not important to you that you can only restore the system to the status of the last available data backup.
Concepts of the Database System, How Databases Log Data Changes
Database Studio, Activating or Deactivating the Overwrite Mode of the Log Area
Database Administration in CCMS, Log Area