2.3. Non - Topological Vector Data
Shapefile A shapefile is a nontopological data structure that does not explicitly store topological relationships. However, unlike other simple graphic data structures, shapefile polygons are represented by one or more rings. A ring is a closed, non-self-intersecting loop. This structure can represent complex structures, such as polygons, that contain "islands." Shapefile stores nontopological geometry and attribute information for the spatial features in a data set. The geometry for a feature is stored as a shape comprising a set of vector coordinates. Because shapefiles do not have the processing overhead of a topological data structure, they have advantages over other data sources such as faster drawing speed and edit ability. This structure was very efficient from a data storage standpoint, but very inefficient for rendering polygons. The shapefile format is a digital vector storage format for storing geometric location and associated attribute information. It is deve...