Optimal Incremental Backup Interval Time Policy

摘要

Suppose that a database is updated at a nonhomo-geneous Poisson process and an amount of updated trucks accumulates additively. Some media failures occur at random. To lessen the overhead of backup processing, the operation of a cumulative backup with small overhead is adopted between the operations of a full backup. The mean time to full backup and the expected cost of these schemes are derived, using the theory of cumulative processes. Further, an optimal number of cumulative backup which minimize the expected costs are analytically discussed. Numerical examples are finally given.