Key Technology Research On Spatial Database Engine

With the rapid development of database technology and distributed object component technology, to create a high performance spatial database engine of GIS is a key research point in computer software. The main content of this thesis is key technology research on spatial database engine (SDE) based on heterogeneous databases.This thesis involves four aspects in key technology of spatial database engine. The first is about the architecture of SDE. This thesis analyzes several typical architectures of SDE currently, puts forward a SDE of hybrid multi-tier architecture which is based on Ice (InternetComunication Engine). A three-tier SDE-Remote SDE based on Ice has strongscalability and can better support interoperation of heterogeneous systems.The second is about the spatial data model of spatial database. This thesis extends the simple feature model of OpenGIS according to the concept model of spatial data. Thus it can support both vector feature and raster feature in a uniform storage method. This thesis analyzes the storage model of ORDB and relational database, finally it brings forward a uniform storage model based on full relational database.The third is about uniform access interface of herterogeneous databases. This thesis analyzes the difference of several heterogeneous databases, implements a uniform SQL language bases on SQL92 standard. Then it implements the atom operations in database level. At last it implements a uniform spatial data access interface based on heterogeneous databases.The fourth is about spatial index algorithm of spatial database. Spatial index algorithm is the most important method to improve spatial query efficiency. This thesis designs and implements an improved linear quadtree spatial index algorithm based on quadtree and spatial filling curves, and puts forward a method to improve the linear quadtree spatial index algorithm.These key technologies apply in the VegaGIS system successfully.