Handling Integrity Constraints of Complex Objects in Spatial Databases

The study reported in this paper is based on two assumptions about the importance of the consistency of a geographical database. Firstly, consistency is an important factor concerning the quality of data. Secondly, consistency of a geographical object requires that the description of the context of the object is a part of the object definition. In object-oriented databases, it is possible to model geographical entities as complex object types whose semantics are captured through constraints on objects and object relationships.This paper examines the modelling of geographical objects and spatial relationships between them. A geometrical object model for geographical entities is presented which consists of 1) the structural definition of the objects, and 2) the enforcement of the implicit structural constraints as object methods. A modelling technique for specifying explicit constraints on spatial relationships between objects is also presented.