Spatio-Temporal Data Types: An Approach to Modeling and Querying Moving
Objects in Databases
Martin Erwig (1), Ralf Hartmut Güting (1), Markus Schneider
(1), Michalis Vazirgiannis (1+2)
(1) Praktische Informatik IV, Fernuniversität Hagen,
D-58084 Hagen, GERMANY,
{erwig, gueting, markus.schneider}@fernuni-hagen.de
(2) Dept. of Informatics, Athens University of Economics and Business,
Patision 76, 10434 Athens, Greece,
mvazirg@aueb.gr
Abstract: Spatio-temporal databases deal with geometries changing
over time. In general, geometries cannot only change in discrete steps,
but continuously, and we are talking about moving objects. If only the
position in space of an object is relevant, then moving point is
a basic abstraction; if also the extent is of interest, then the moving
region abstraction captures moving as well as growing or shrinking
regions. We propose a new line of research where moving points and moving
regions are viewed as three-dimensional (2D space + time) or higher-dimensional
entities whose structure and behaviour is captured by modeling them as
abstract data types. Such types can be integrated as base (attribute) data
types into relational, object-oriented, or other DBMS data models; they
can be implemented as data blades, cartridges, etc. for extensible DBMSs.
We expect these spatio-temporal data types to play a similarly fundamental
role for spatio-temporal databases as spatial data types have played for
spatial databases. The paper explains the approach and discusses several
fundamental issues and questions related to it that need to be clarified
before delving into specific designs of spatio-temporal algebras.
Keywords: Spatial, temporal, spatio-temporal, data types,
moving objects, moving point, moving region
Published: FernUniversität Hagen, Informatik-Report
224, December 1997. To appear in GeoInformatica 3:3, 1999.