Capturing XML constraints with relational schema

The use of XML as the common format for representing, exchanging, and accessing data poses many new challenges to XML storage systems. One way to this goal is to store XML data in relational databases in order to use relational database techniques. Although several approaches exist, they focus only on XML data aspects and ignore semantic constraints. In the paper, we analyze structural and semantic constraints in XML, and then we discuss how to capture and map these constraints with relational schema. Comparing with existing methods, our approach can preserve more XML constraints and reduce nesting and redundant data.