An ORDBMS Based GIS Data Management Model and Its Realization

Efficient spatial data management is a key issue of GIS technology. Object-relational database, because of its advantage in data sharing, security and transferring in network, is recognized as an effective tool for GIS data management, and many studies on this area have shown great success. But in actual application with large quantity of data, some difficulties still exist. This paper, based on the analysis of the features of Raster and vector data and the applicability of Object-Relational database to the management of GIS data, presented a practical integration model for the two types of data in GIS. This integrated spatial data model was applied to the GIS software-ViewGIS, which was successfully used in building the provincial forestry GIS of Hunan province in 2003.The ORDBMS based GIS spatial data model, which uses Oracle Spatial mechanism for vector data and RDB LOB mechanism for raster data respectively, realized the goal of managing raster and vector data in the same database. This can not only greatly benefit end users with remote data access, data manipulation and other mechanisms of the database, but also avoid the barrier of unopened data structure in ArcSDE and has higher efficiency.