Minimizing View Sets without Losing Query-Answering Power

  • Chen Li
  • Mayank Bawa
  • Jeffrey D. Ullman
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1973)

Abstract

The problem of answering queries using views has been studied extensively due to its relevance in a wide variety of data-management applications. In these applications, we often need to select a subset of views to maintain due to limited resources. In this paper, we show that traditional query containment is not a good basis for deciding whether or not a view should be selected. Instead, we should minimize the view set without losing its query-answering power. To formalize this notion, we first introduce the concept of “p-containment.” That is, a view set V is p-contained in another view set W, if W can answer all the queries that can be answered by V. We show that p-containment and the traditional query containment are not related. We then discuss how to minimize a view set while retaining its query-answering power. We develop the idea further by considering p-containment of two view sets with respect to a given set of queries, and consider their relationship in terms of maximally-contained rewritings of queries using the views.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • Chen Li
    • 1
  • Mayank Bawa
    • 1
  • Jeffrey D. Ullman
    • 1
  1. 1.Computer Science DepartmentStanford UniversityUSA

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