An Object-Relational Approach to the Representation of Multi-granular Spatio-Temporal Data

The notion of spatio-temporal multi-granularity is fundamental when modeling objects in GIS applications in that it supports the representation of the temporal evolutions of these objects. Concepts and issues in multi-granular spatio-temporal representations have been widely investigated by the research community. However, despite the large number of theoretical investigations, no comprehensive approaches, have been proposed dealing with the representation of multi-granular spatio-temporal objects in commercially available DBMSs. The goal of the work that we report in this paper is to address this gap. To achieve it, the paper first introduces an object-relational model based on OpenGis specifications described in SQL3. Several extensions are developed in order to improve the semantics and behavior for spatio-temporal data types introducing an approach to represent the temporal dimension in this model and the multi-representation of spatio-temporal granularities.