COMPOSITE REGIONS IN TOPOLOGICAL QUERIES

Spatial data are at the core of many scientific information systems. The design of suitable query languages for spatial data retrieval and analysis is still an issue on the cutting edge of research. The primary requirement of these languages is to support spatial operators. Unfortunately, current systems support only simplified abstractions of geographic objects based on simple regions which are usually not sufficient to deal with the complexity of the geographic reality. Composite regions, which are regions made up of several components, are necessary to overcome those limits. The paper introduces a two-level formal model suitable for representing topological relationships among composite regions. The contribution gives the needed formal background for adding composite regions inside a spatial query language with the purpose of answering topological queries on complex geographic objects.