Transforming XML Documents as Schemas Evolve

Database systems often use XML schema to describe the format of valid XML documents. Usually, this format is determined when the system is designed. Sometimes, in an already functioning system, a need arises to change the XML schemas. In such a situation, the system has to transform the old XML documents so that they conform to the new format and that as little information as possible is lost in the process. This process is called schema evolution. The authors have implemented an XML schema transformation toolkit within IBM Master Data Management Server (MDM). MDM uses XML documents to describe products that an enterprise may be offering to its clients.