Storing Linked XML documents in Object-Relational DBMS

Abstract

Currently, several researchers have proposed mapping both structure and constraints of XML documents to an object-relational database (ORDB). However these researches cannot be conducted because of the limited range of constraints in available object-relational DBMSs. We therefore propose mapping rules that are practicable in available technologies. Normally, an XML document is treated as a database so much data redundancy occurs. To solve this problem, we keep non-redundant data in several separate XML documents, link the data dispersed in these documents together by a mechanism called ‘rlink’ and then map this mechanism to ORDB. Finally we perform a case study in Oracle9i to illustrate the mapping of XML to ORDB according to our rules. Our contribution is that we find that mapping linked XML documents to traditional databases such as (O)RDB makes it easier to join several documents and to update several documents in one update command.