earticle

영어

Transformation of a source schema with its conforming data to a target schema is an important activity in data integration with any data model. In last decade, with the advent of XML as an widely used and adopted data representation and storage format over the web, the task of data transformation for the purpose of data integration solely in XML is getting much attention to the database researchers and application developers. In XML data transformation, when an XML source schema with its conforming data is transformed to the target XML schema, one of the important XML constraints, XML keys that are defined on the source schema for expressive semantics can also be transformed. Thus, whether keys should be transformed and preserved, and if not preserved, whether keys can be captured in another form of XML constraints are important research questions. To answer these questions, first, we define XML keys and XML Functional Dependencies(XFD) on Document Type Definition(DTD). Second, we show key preservation in transformation. If keys are not preserved, we then show how to capture them as XFDs. We term this as key transition. Our research on XML key preservation and transition is towards handling the issues of integrity constraints in XML data integration.