Processing Object-Orientation-based Direction Queries in Spatial Databases

Direction based spatial relationships are critical in many domains including geographic information systems(GIS) and image interpretation. They are also frequently used as selection conditions in spatial queries. In this paper, we explore processing of queries based on object-orientation-based directional relationships. A new Open Shape based strategy(OSS) is proposed. OSS converts the processing of the direction predicates to the processing of topological operations between open shapes and closed geometry objects. Since OSS models the direction region as an OpenShape, it does not need to know the boundary of the embedding world, and also eliminating the computation related to the world boundary. We perform algebraic analysis as well as experimental evaluation for OSS. The experimental result demonstrates that the OSS consistently outperforms classical range query strategy both in I/O and CPU cost. the content of which does not necessarily reeect the position or the policy of the government, and no oocial endorsement should be inferred.