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A practical guide to the design of differential files for recovery of on-line databases

The concept of a differential file has previously been proposed as an efficient means of collecting database updates for on-line systems. This paper studies the problem of database backup and recovery for such systems, and presents an analytic model of their operation. Five key design decisions are identified and an optimization procedure for each is developed. A design algorithm that quickly provides parameters for a near-optimal differential file architecture is provided.