Optimal backup policy for the incremental backup and reliability analysis

摘要

A database is updated at a nonhomogeneous Poisson process, and an amount of updated trucks accumulates additively. Some media failures occur at random. To lessen the overhead of backup processings, the operation of an incremental backup with small overhead is adopted between the operations of a full backup. This paper considers three backup polices for the incremental backup in a database system: The reliability measures of these models are derived, using the theory of cumulative processes. The comparisons between two schemes of incremental backup are made. Specifically, an optimal backup scheme and an optimal time of a full backup are derived.