New rollback records added to the transaction log in 11.9.2 may require you to add more space to the syslogs system table. Rollback records are logged whenever a transaction is rolled back. For every update record that is rolled back, a rollback record is logged.
To make sure that there is always space for rollback records in the event of a rollback, ASE saves enough space to log a rollback record for every update belonging to an open transaction. If a transaction completes successfully, no rollback records are logged and the space reserved for them is released.
To calculate the increased amount of space that needs to be added to the transaction log to accommodate rollback records, you need to estimate:
The number of update records in the transaction log that are likely to belong to already rolled-back transactions.
The maximum number of update records in the transaction log that are likely to belong to open transactions at any one time.
Each rollback record requires approximately 60 bytes of space, or 3 one hundredths of a 2K page. Thus, the calculation for including rollback records (RRs) in the transaction log is:
(logged RRs + # open updates) * 3/100
In addition to increasing the size of the transaction log to handle rollback records, it may also be useful to add log space to compensate for the effects of rollback records on the last-chance threshold (LCT) and on user-defined thresholds.
