Temporal Objects for Spatio-Temporal Data Models and a Comparison of Their
Representations
Martin Erwig, Markus Schneider, and Ralf Hartmut Güting
Praktische Informatik IV, Fernuniversität Hagen, D-58084 Hagen,
GERMANY,
{erwig, markus.schneider, gueting}@fernuni-hagen.de
Abstract: Currently, there are strong efforts to integrate
spatial and temporal database technology into spatio-temporal database
systems. This paper views the topic from a rather fundamental perspective
and makes several contributions. First, it reviews existing temporal
and spatial data models and presents a completely new approach to temporal
data modeling based on the very general notion of temporal object.
The definition of temporal objects is centered around the observation that
anything that changes over time can be expressed as a function over time.
For the modeling of spatial objects the well known concept of spatial data
types is employed. As specific subclasses, linear temporal and spatial
objects are identified. Second, the paper proposes the database embedding
of temporal objects by means of the abstract data type approach to the
integration of complex objects into databases. Furthermore, we make
statements about the expressiveness of different temporal and spatial database
embeddings. Third, we consider the combination of temporal and spatial
objects into spatio-temporal objects in (relational) databases. We
explain various alternatives for spatio-temporal data models and databases
and compare their expressiveness. Spatio-temporal objects turn out
to be specific instances of temporal objects.
Keywords: Spatial, temporal, spatio-temporal, data types, moving
objects, moving point, moving region
Published: Advances in Database Technologies (ER '98
Workshop on Spatio-Temporal Data Management), LNCS 1552, 454-465, 1998.