Last-chance threshold

If a transaction log is on its own segment (that is, if a segment is mapped to a device on which a database has allocated log-only space), Adaptive Server automatically creates a last-chance threshold on the segment, along with any other thresholds that you add. This threshold is an estimate of the number of free log pages that would be required to back up the transaction log. Adaptive Server automatically adjusts the last-chance threshold as you allocate more space to the log segment.