Minimizing View Sets without Losing Query-Answering Power

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 rst 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 m...

• Type: Conference
• Year: 2001
• Where: ICDT
• Authors: Chen Li, Mayank Bawa, Jeffrey D. Ullman
• Keywords: Database, ICDT 2001, Query-answering Power, Traditional Query Containment, View Sets