The Last-Chance Threshold

By default, the SAP ASE server monitors the free space on the segment where the log resides and executes sp_thresholdaction when the amount of free space is less than that required to permit a successful dump of the transaction log. This amount of free space, called the last-chance threshold, is calculated by the SAP ASE server and cannot be changed by users.

If the last-chance threshold is crossed before a transaction is logged, the SAP ASE server suspends the transaction until log space is freed. Use sp_dboption to change this behavior for a particular database sp_dboption "abort tran on log full", true causes the SAP ASE server to roll back all transactions that have not yet been logged when the last-chance threshold is crossed.

All databases have a last-chance threshold, including master. The threshold is an estimate of the number of free log pages that are required to back up the transaction log. As you allocate more space to the log segment, the SAP ASE server automatically adjusts the last-chance threshold.