Abstract

The XML database community felt the necessity for incorporating explicit constraint specification schemes for XML, so that XML may be used for database applications. This was one of the reasons for a new schema language standard called W3C XML-Schema, in place of DTD, the original standard. However, several fundamental problems exist in XML constraint specification today, which are yet to be solved. This talk is an attempt to investigate answers to some of these questions. We study explicit constraint specification requirements for XML using the following assumption: An XML schema language should provide the ability to specify a normalized XML schema to model any database application scenario. Using this approach, we are able to systematically come up with a constraint specification scheme for XML.