National Center for Geographic Information and Analysis

This unit provides background on the debate about “object-oriented databases” currently raging in the GIS community. It describes the layer view, in which each geographic variable can be conceptualized as a layer that captures the variable’s variation over the surface of the earth, and the object view, in which the world is conceptualized as empty space littered with various types of objects. Data models for representing each view are discussed in addition to the Computer Science concepts of object orientation, identity, inheritance and encapsulation.