On-line algorithm of loose competitive caching

Abstract

In response to a sequence of requests for files, where each file has a specified size and retrieval cost, the total size of each file in cache was maintained at some specified k so as to minimize the total retrieval cost. A simple deterministic on-line algorithm was proposed. In this algorithm, many well-known paging and weighted caching strategies were generalized, and the retrieval cost was either insignificant or at most a constant (independent of k) times the optimum value for most k. This helps explain why competition ratios of many on-line paging algorithms have been typically observed to be constant in practice.