On-line stream merging, max span, and min coverage

Abstract

This paper introduces the notions of span and coverage for analyzing the performance of on-line algorithms for stream merging. We show that these two notions can solely determine the competitive ratio of any such algorithm. Furthermore, we devise a simple greedy algorithm that can attain the ideal span and coverage, thus giving a better performance guarantee than existing algorithms with respect to either the maximum bandwidth or the total bandwidth. The new notions also allow us to obtain a tighter analysis of existing algorithms. © Springer-Verlag Berlin Heidelberg 2003.