Converting XML Schema into Object-Relational Model with Data Constraints Preservation

Abstract

XML is widely used for data exchange between systems and applications. XML data are described in hierarchical form using XML schema languages such as XML DTD (Document Type Definition), W3C XML Schema or XDR (XML Data Reduced). To make these data accessible to relational database systems, which represent a dominant and efficient tool for storing and retrieving structured data, schema conversion methods must be developed. The early conversion methods have focused on mappings between DTDs and relational model. But, due of the needs to hold complex data, certain relational database builders have evolved their systems into object-relational model. Meanwhile, XML Schema language developed to describe data in more detail than DTD is a mature technology.  So, in this paper we propose a methodology for translating data described in XML Schema language into object-relational model. This translation preserves integrity constraints defined in XML Schema and uses composition of conversions.