Accessing and Transforming Dynamic Content based on XML: Alternative Techniques and a Practical Implementation1

XML is widely used as a Web language that decouples completely the data model from the various views that may be employed to present the actual information. Using XML in the scope of information portals, auctions and e-publishing applications constitutes often a compromise between transformation flexibility, scalability and the required computing power. Thus, most large scale Web based applications, featuring databases access and dynamic content presentation rely on RDBM back end systems. In the scope of these systems XML is usually employed as a data layer hiding the peculiarities of the particular database system and schema. This paper reviews popular architectures for combining XML and RDBM systems and illustrates one of these architectural alternatives through a detailed presentation of the practical implementation of a novel back end system. This system is developed in the scope of the CATCH2004 (IST 1999-11103) research initiative, in order to support the data tier of a multimodal, multilingual and multi-device information retrieval system.