Querying by Spatial Structure

Structural queries constitute a special form of content-based retrieval where the user specifies a set of spatial constraints among query variables and searches for all configurations of actual objects that (totally or partially) match these constraints. Processing of such queries can be thought of as a general form of spatial joins, i.e., instead of pairs, the result consists of n-tuples of objects, where n is the number of query variables. In this paper we propose a flexible framework which permits the representation of configurations in different resolution levels and supports the automatic derivation of similarity measures. We subsequently describe three algorithms for structural query processing which integrate constraint satisfaction with spatial indexing. For each algorithm we apply several optimization techniques and experimentally evaluate performance using real data. Abstract Tracking Number: 628Tracking Number: 628 Correspondence should be addressed to Dimitris Papadias. Tel: ++852-2358-8218, Fax: ++852-2358-6971