The Worst Page-Replacement Policy

In this paper, we consider the question: what is the worstossible page-replacement strategy? Our goal is to devise an online strategy that has the highest possible fraction of misses as compared to the worst offline strategy. We show that there is no deterministic, online page-replacement strategy that is competitive with the worst offline strategy. We give a randomized strategy based on the "most-recently-used" heuristic, and show that this is the worst possible online page-replacement strategy.