OnlineMin: A Fast Strongly Competitive Randomized Paging Algorithm
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In the field of online algorithms paging is one of the most studied problems. For randomized paging algorithms a tight bound of H k on the competitive ratio has been known for decades, yet existing algorithms matching this bound have high running times. We present a new randomized paging algorithm OnlineMin that has optimal competitiveness and allows fast implementations. In fact, if k pages fit in internal memory the best previous solution required O(k 2) time per request and O(k) space. We present two implementations of OnlineMin which use O(k) space, but only O(logk) worst case time and O(logk/loglogk) worst case time per page request respectively.
KeywordsOn-line algorithms Competitive analysis Paging Randomized algorithms
We would like to thank previous anonymous reviewers for very insightful comments and suggestions. Also, we would like to thank Annamária Kovács for useful advice on improving the presentation of the paper.
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