Departmental Papers (CIS)
Date of this Version
January 2009
Document Type
Conference Paper
Recommended Citation
Sudipto Guha, "Tight results for clustering and summarizing data streams", . January 2009.
Abstract
In this paper we investigate algorithms and lower bounds for summarization problems over a single pass data stream. In particular we focus on histogram construction and K-center clustering. We provide a simple framework that improves upon all previous algorithms on these problems in either the space bound, the approximation factor or the running time. The framework uses a notion of ``streamstrapping'' where summaries created for the initial prefixes of the data are used to develop better approximation algorithms. We also prove the first non-trivial lower bounds for these problems. We show that the stricter requirement that if an algorithm accurately approximates the error of every bucket or every cluster produced by it, then these upper bounds are almost the best possible. This property of accurate estimation is true of all known upper bounds on these problems.
Keywords
data streams, clustering
Date Posted: 10 January 2009
This document has been peer reviewed.