| XML is increasingly gaining ground as a standard for data representation and exchange over the web. XML data most often has some embedded structure; therefore, it is interesting to exploit this structure whenever present. The structure of an XML document can be modeled by DTDs, XML Schema, or XQuery types. Both XML Schema and XQuery have a type system that supports a subtyping relation between types.; The purpose of this thesis is to develop an indexing mechanism, called Tindex, that efficiently retrieves supertypes of an XML type. We consider XQuery types and DTDs, and our indexing mechanism can be extended to XML Schema. The main research challenge for indexing XML types is the complex nature of terms to index, i.e. terms are regular expressions. Tindex can be used in query optimization, storage optimization, data integration, and XML data repositories. |
