Processing Object-orientation-based Direction Queries: A summary of Results

ABSTRACT Dire tion based spatial relationships are riti al in many domains in luding geographi information systems(GIS) and image interpretation. They are also frequently used as sele tion onditions in spatial queries. In this paper, we explore the pro essing of queries based on obje t-orientation-based dire tional relationships. A new open shape based strategy(OSS) is proposed. OSS onverts the pro essing of the dire tion predi ates to the pro essing of topologi al operations between open shapes and losed geometry obje ts. Sin e OSS models the dire tion region as an OpenShape, it does not need to know the boundary of the embedding world, and also eliminating the omputation related to the world boundary. The experimental evaluations show that OSS onsistently outperforms lassi al range query strategy both in I/O and CPU ost. This paper is a summary of the results.