An automatic navigation scheme for XML documents through object-relational repository

XML (eXtensible Markup Language), a simplified version of SGML (Standard Generalized Markup Language), is designed to enable electronic text interchange via the Internet. Most current approaches store XML documents in file systems or in relational database systems. However, the nature and the design of file systems or relational database schemas cannot fit with the XML document structure very well. In this paper, we propose an automatic navigation scheme to store and retrieve XML documents through object-relational databases. We have designed a system architecture, called XMG (XML Meta-Generator), which, after reading a specific DTD (document type definition), automatically generates the corresponding object-relational database schema (OR-schema), a document instance (DI) decomposer and a DI reconstructor. These modules automatically decompose and reconstruct XML documents into/from object-relational databases in a seamless manner. Moreover, documents stored in the object-relational databases can be managed and queried more easily than they could be in file systems or relational databases. Useful applications on various documents can also be easily built, such as digital libraries, data warehousing and data- or text-mining systems