MANAGEMENT OF UNITS OF WORK ON A COMPUTER SYSTEM LOG

摘要

A method of moving records, stored on a recovery log (900), which are associated with units of work which have waited for a long time is described. Units of work which have waited for a long time, such as those which are in-doubt have their records copied from a recovery log (900) to a secondary log (950). When the earliest-written record (710) for this in-doubt unit of work has been copied, a new record (910) called a fork record is written on to the recovery log (900) which has two effects: to subtract the log records (710, 725, 750) currently on the recovery log (900) for this unit of work from the recovery log (900) and to refer to the copied records (711, 726, 751) written on the secondary log (950). The new record (910) achieves this using two pointers, a pointer (970) to point to the most-recently written record (770) on the recovery log (900) for this unit of work and a pointer (960) to point to the most-recently written record (751) on the secondary log (950) for this unit of work.