Report Number: CS-TR-97-1583
Institution: Stanford University, Department of Computer Science
Title: Boolean Query Mapping Across Heterogeneous Information Sources (Extended Version)
Author: Chang, Kevin Chen-Chuan
Author: Garcia-Molina, Hector
Author: Paepcke, Andreas
Date: January 1997
Abstract: Searching over heterogeneous information sources is difficult because of the non-uniform query languages. Our approach is to allow a user to compose Boolean queries in one rich front-end language. For each user query and target source, we transform the user query into a subsuming query that can be supported by the source but that may return extra documents. The results are then processed by a filter query to yield the correct final result. In this paper we introduce the architecture and associated algorithms for generating the supported subsuming queries and filters. We show that generated subsuming queries return a minimal number of documents; we also discuss how minimal cost filters can be obtained. We have implemented prototype versions of these algorithms and demonstrated them on heterogeneous Boolean systems.