Scalable query rewriting: a graph-based approach

In this paper we consider the problem of answering queries using views, which is important for data integration, query optimization, and data warehouses. We consider its simplest form, conjunctive queries and views, which already is NP-complete. Our context is data integration, so we search for maximally-contained rewritings. By looking at the problem from a graph perspective we are able to gain a better insight and develop an algorithm which compactly represents common patterns in the source descriptions, and (optionally) pushes some computation offline. This together with other optimizations result in an experimental performance about two orders of magnitude faster than current state-of-the-art algorithms, rewriting queries using over 10000 views within seconds. Categories and Subject Descriptors H.2.4 [Database Management]: Systems—Query processing; H.2.5 [Database Management]: Heterogeneous Databases; G.2.2 [Discrete Mathematics]: Graph Theory—Hypergraphs General Terms Algori...

• Type: Journal
• Year: 2011
• Where: SIGMOD
• Authors: George Konstantinidis, José Luis Ambite
• Keywords: Data Warehouses, Database, Database Management Systems, Heterogeneous Databases, SIGMOD 2011