Model-Driven Approach to XML Schema Evolution

Abstract

Today, XML is a standard meta-language for representation of exchanged messages between information systems. To enable exchange, the structure of the messages must be established in a form of XML schemas. Usually, more than one type of messages is exchanged and, hence, a family of XML schemas needs to be created. An important task for the designer is, therefore, to design the XML schemas and then evolve them continuously as user requirements change. Doing this manually may be very difficult due to the fact that single change in the user requirements may impact many XML schemas. In this paper, we present a novel approach to evolution of families of XML schemas. It is based on modeling XML schemas at two levels - conceptual and XML schema. The designer performs a change only once in the conceptual schema and our introduced mechanism propagates the change to all affected XML schemas. Propagation from the XML schema to the conceptual level is also supported.