XML and system interoperability

Systems interoperability aims to enable simplified communication between systems, in order to facilitate exchanges. To achieve such interoperability, especially in a heterogeneous context, XML (eXtensible Markup Language) [H 7 148][H 3 500] has become the preferred exchange format, since it is independent of the processes that produce and use it. It enables data to be structured semantically, making content independent of any formatting.

While XML solves many of the problems associated with data exchange, there are other points to consider when it comes to managing the content exchanged. A few ideas are given in [H 3 502] . Our aim here is to detail the different ways of accessing XML data, depending on the type of processing you wish to carry out.

Data can be accessed via XML document parsers such as DOM (Document Object Model) or SAX (Simple API for XML), via a transformation language such as XSL-T (eXtensible StyleSheet Language Transformation), or directly via XQuery queries. Of course, the choice of access depends on the processing required on the documents, but also on the storage mode chosen.

Based on a case study presented in the 1 section of this document, we detail three possible solutions for storing and processing data from an XML document exchanged between two systems (it is assumed that the document structure is known).

The first would be to use a purely structured approach: XML data would be stored in relational tables, with XML-relational...