The Research Of Spatial Data Index And Application In GIS

Spatial databases are being applied widely in many applications such as GIS, CAD, Robot, Computation, Geometry, Computer Vision, Physic Image and Multimedia System etc. Along with the concepts of Cyber-City, Digit Earth and Cyber-River being put forward and applied, the higher efficiency of storing and processing spatial data is demanded. Spatial index is vital technique for improving the performance of spatial databases. It affects the storage efficiency and spatial retrieve performance of spatial data directly. Studying spatial data index techniques and investigating better spatial index mechanisms have been a focus of reseach in the computer circles and other application field.In non-standard database applications, such as geographic information processing or CAD/CAM, methods of access are required that support efficient manipulation of multidimensional geometric objects on secondary storage. The methods also need retrieve spatial data via exact match queries and range queries from large, dynamic index. At present, all of spatial index, especially the R-tree and its variation which are being used in a large range, have obvious weakness in high frequently accessing data in secondary storage and processing multidimensional spatial objects. Otherwise, the performance of most spatial index in existence drops quickly with the large increase of spatial data or spatial dimension.The paper discusses the spatial index's related concept, data structure, arithmetic of dynamic index, analysis of performance. After the large quantity of research in spatial data index technique, the paper introduces a spatial index structure based region encode—Region Encode-tree which adopts the thinking of region encode and aims to the problem which introduced in two paragraph. The data structure and related dynamic operation of the new spatial index are also introduced. From the comparison with R-tree, R~+-tree, R~*-tree, Region Encode-tree has high performance in operation of insert, delete, especially search. Region Encode-tree applies in Dalian Land Planning Management Information System which is based Arclnfo platform. The system gives up the quadtree index which used in shp format file of Arclnfo platform and makes use of Region Encode-tree. Although not high in spatial utilization, the new spatial index structure has more high performance in search, insert and delete from many experiments.