The GEO VIEW design: a relational database approach to geographical data handling

Digital map data are currently available based on a variety of data structures, depending on the uses to which the data are to be put Within the major categories of vector and raster data, as well as other structures, there is a multiplicity of data formats. Further to this, data for digital map coordinates are frequently stored in a different way from attribute data pertaining to points, lines and polygons. Given these problems, this paper investigates the possibility of handling different kinds of data structures, as well as both coordinate and attribute information within a unified conceptual scheme. This scheme is expressed in terms of the design of an integrated geographical information system called GEO VIEW, which can be implemented in a relational data base environment. The structure of the tables in the data base is outlined, together with the methodology for coding different kinds of data structure into a standard form. Examples of queries are provided, using the SQL query language, to indicate how the system might be used and problems in optimizing spatial searching on a data base of this kind are addressed.