Implementation of UML Schema in Relational Databases: A Case of Geographic Information

Numerous disciplines require information concerning phenomena implicitly or explicitly associated with a location relative to the Earth. Disciplines using Geographic Information (GI) in particular are those within the earth and physical sciences, and increasingly those within social science and medical fields. Therefore geographic datasets are increasingly being shared, exchanged and frequently re-purposed for uses beyond their original intended use. Being part of the ISO 19100 Geographic Information Standard series, the ISO 19136 called Geography Markup Language (GML), defines the rules a data model described using the Unified Modeling Language (UML) has to follow in order to generate from it an XSD schema. However, if GML is essential for exchange data among different organization, it may not be the best option for persisting or searching operations. On the other side, the Relational Database Model (RDBM) has been heavily optimized over the decades to store and search data. This paper does not address "How to store an GML complaint document in an RDBM" but "How to realize an RDBM from an ISO 19100 complaint UML data model" and within this context, it describes the experience and the lessons learnt. The conclusions show how the information contained in such UML is able to produce not only representations as GML schema, but also RDBM or RDF without passing by any intermediary step.