We designed a concise way to store and manipulate GIS coverage data in a geospatial database. Our
geospatial database is implemented with PostgreSQL and PostGIS. PostgreSQL is an object-relational
database, and PostGIS supports various geospatial operations as an SQL extension. In our Oregon
Relational Spatial Topology (ORST) approach, topological relationships among polygons, arcs, and
points are represented explicitly. With this explicit representation of polygon data, such spatial
operations as moving a point, merging a polygon, and splitting a polygon can be supported with relative
ease. In order to populate this database, we developed a process for converting polygon data stored as
an ESRI shapefile first to the ESRI E00 coverage format and then to the ORST representation. We also
implemented the spatial operations discussed above.