Minimizing The I/O-Operations For Undo-Logging In Database Systems

A special UNDO-log algorithm combining the advantages of update-in-place strategies with the shadow page concept is introduced. It is to support applications demanding high rates of updating transactions as well as fast UNDO-recovery. By doubling the disk space for the database UNDO-logging can be performed with a minimum of additional I/O-operations. Thus we gain a performance comparable to systems without any UNDO-logging.