XML schema harmonization: design methodology and examples

The flexible and semi-structured eXtensible Markup Language (XML) is used in various application domains as well as the database field. The proposed XML harmonization system attempts to re-utilize existing markup languages by extracting and integrating them. This idea is analogous to the join operation in the database domain. When new structures are created, new document types are defined. Structures of XML instances can be viewed from various viewpoints, e.g. the relational database or the object-oriented database. In this work, we propose a new way to achieve harmonization, i.e., by defining axioms on atomic elements of the selected data structure. The advantage of using axioms is that it can be extended to other data structures easily. Measurements of harmonization are discussed, and harmonization examples are given to illustrate the axiom-based design principle.