BRIDGING AN OBJECT ORIENTED GIS APPLICATION AND RELATIONAL DBMS Stoimenov Leonid CG & GIS Lab, Faculty of Electronic Engineering, University of Ni{ Beogradska 14, 18000 Ni{, Yugoslavia Antonija Mitrovi} Department of Computer Science, University of Canterbury New Zealand Slobodanka \or|evi}-Kajan, Dragan Stojanovi} Computer Graphics & GIS Lab Tel: (+381) 18 41 946, Fax: (+381) 18 46 180 e-mail: leni@europa.elfak.ni.ac.yu ABSTRACT This paper presents a methodology to coupling object-oriented GIS applications with relational databases. Most problems with GIS applications come from inadequacies and low expressiveness of computational models used and the impedance mismatch problem. The object-oriented paradigm is a natural one for highly complex domains such as ones involving spatial entities, because it maintains a direct correspondence between real-word and application objects. Paper presents GinisNT, a scalable, OO framework for developing GIS applications which is actually implemented on top of the relational data model. GinisNT framework provide automatic mapping between the two data models, thus making the usage of a RDBMS transparent to the user. 1. Introduction Lower costs of computer hardware and general awareness of effectiveness and usefulness of GISs have had valuable impacts on their wider application. However, numerous problems still remain, especially in the development of end-user GIS applications. GIS software is very complex and the tools for developing applications, most often in the form of macro languages, typically have restricted functionality. Data models on which GIS software is based have been developed with spatial data in mind, and are not readily extendible to support other real-world problems. Numerous legacy systems should be coupled with GIS systems, which present additional difficulties in developing end-user applications. The research group at the Computer Graphics and GIS Lab at the University of Nis, Yugoslavia has been developing GIS software for eight years now. One of the research