A Randomized Online Quantile Summary in O((1/ε) log(1/ε)) Words
A Randomized Online Quantile Summary in O((1/ε) log(1/ε)) Words
复制标题
O((1/ε) log(1/ε)) 个字的随机在线分位数摘要
作者:
David Felber;R. Ostrovsky
A quantile summary is a data structure that approximates to $varepsilon$-relative error the order statistics of a much larger underlying dataset.
In this paper we develop a randomized online quantile summary for the cash register data input model and comparison data domain model that uses $O(frac{1}{varepsilon} log frac{1}{varepsilon})$ words of memory. This improves upon the previous best upper bound of $O(frac{1}{varepsilon} log^{3/2} frac{1}{varepsilon})$ by Agarwal et. al. (PODS 2012). Further, by a lower bound of Hung and Ting (FAW 2010) no deterministic summary for the comparison model can outperform our randomized summary in terms of space complexity. Lastly, our summary has the nice property that $O(frac{1}{varepsilon} log frac{1}{varepsilon})$ words suffice to ensure that the success probability is $1 - e^{- ext{poly}(1/varepsilon)}$.