Global Access to Environmental Information
Ralf Krämer, Tom Quellenberg · 1996
Environmental applications deal with huge numbers of knowledge domains. In order to cope with the increasing number of highly diverse data and information sources, explicit modelling of meta-data is mandatory. This paper focuses on how data in an existing meta-data model, originally developed for German authorities, can be accessed in wide-area networks. The current implementation combines navigational access methods via Mosaic and declarative access through SQL. The system architecture and query processing in that architecture are described. Lessons learned from the initial system concern the necessity for design recovery when using an existing meta-data model and experiences obtained from using the stateless World-Wide Web (WWW) environment in database applications. Looking ahead, we sketch the active information system that will support access to semantically heterogeneous information sources in the future.