Stanford InfoLab Publication Server

Predicate Rewriting for Translating Boolean Queries in a Heterogeneous Information System

Chang, Chen-Chuan K. and Garcia-Molina, Hector and Paepcke, Andreas (1999) Predicate Rewriting for Translating Boolean Queries in a Heterogeneous Information System. ACM Transactions on Information Systems, vol. 17, no. 1, Jan. 1999 .




Searching over heterogeneous information sources is difficult in part because of the non-uniform query languages. Our approach is to allow users 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 results. In this paper we introduce the architecture and associated mechanism for query translation. In particular, we discuss techniques for rewriting predicates in Boolean queries into native subsuming forms, which is a basis of translating complex queries. In addition, we present experimental results for evaluating the cost of post-filtering. We also discuss the drawbacks of this approach and cases when it may not be effective. We have implemented prototype versions of these mechanisms and demonstrated them on heterogeneous Boolean systems.

Item Type:Article
Additional Information:Previous number = SIDL-WP-1997-0080
Subjects:Computer Science > Digital Libraries
Projects:Digital Libraries
Related URLs:Project Homepage
ID Code:414
Deposited By:Import Account
Deposited On:29 Oct 2001 16:00
Last Modified:07 Oct 2008 12:14

Download statistics

Repository Staff Only: item control page