Stateful relational database gateways for the World Wide Web

The World Wide Web is currently considered as the most appropriate software platform for the deployment of applications in wide area networks (telematics) as well as corporate intranets. Such applications are, in the majority of cases, tightly coupled with legacy databases hosted by relational management systems. However, the nature of the database enabled WWW systems is quite different from that of classical database applications developed with tools like 4GLs, Forms, Menus, etc. The basic difference lies in the stateless character of the WWW. The 'user session' concept, encountered in conventional database applications, does not apply in the WWW environment. Instead, interaction with the information server is accomplished through a series of hits (request-response interactions) which are treated independently. This paper presents an architecture for the deployment of stateful database gateways for WWW servers. Although the server still treats each individual hit independently, state information maintained in the WWW browser as well as in specialized agents that operate behind the WWW server renders the WWW appropriate for a 'session-aware' database application. The effort required to port an existing 'session-aware' database application to the WWW environment is minimal. (C) 1999 Elsevier Science Inc. All rights reserved.