Research on Holistic Index Method of Geography Markup Language

Currently, the OGC GML (Geography Markup Language) specification has been the de facto standard for GIS data sharing and exchanging and spatial interoperation. Adopting nested association expression approach of XML data, GML data documents can store both spatial information and semantic relationship information of geographical elements. To improve the efficiency of path query on GML two type information, the paper describes a holistic index method for GML data, which we call EKR+ (optimized R⁺-tree base on Extend Region Code and K-means extent partition of GML feature elements). The experiment results show that the efficiency of semantic-spatial query can be improved greatly by utilizing EKR⁺.