From XML schema to object-relational database: an XML schema-driven mapping algorithm

Since XML becomes a crucial format for representing information, it is necessary to establish techniques for managing XML documents. A possible solution can be found in storing XML data in (object-)relational databases. For this purpose most of the existing techniques often exploit an XML schema of the stored XML data, usually expressed in DTD. But the more complex today’s applications are, the more insufficient the DTD becomes and the necessity to use XML Schema language becomes more essential. The paper proposes an algorithm for mapping XML Schema structures to an object-relational database schema (defined by the SQL:1999 standard) using a (modified) DOM interface and an algorithm for storing the valid XML data into relations of the resulting schema. The main aim is to exploit object-oriented features XML Schema has and the advantages of object-relational databases and to preserve the structure as well as semantic constraints of the source schema in the target schema.