Semistructured Data Store Mapping with XML and Its Reconstruction

Abstract. XML has been quickly emerging as a dominant standard for data representation and exchange on the World Wide Web for its many good features such as well-formed structure or semantic support. Research on semistructured data over the last several years has focused on data models, query languages, and systems where the database is modeled in some form of a labeled, directed graph. Processing this as a sophisticated query on semistructured data is not very easy because of the complexity of the structure of the graph and the lack of corresponding schemata associated with it. To deal with such problems the paper proposes an approach to process semistructured data with XML. Although there are many similarities between semistructured data and XML there exist some differences. A key difference is that current XML DOM only supports tree structures and does not directly support graph structures. To deal with such differences two approaches in this paper are proposed to treat an XML document as a semantic graph and literal tree which are the foundation to transform semistructured data into XML documents for processing. For this purpose several algorithms are designed to transform semistructured data into XML documents and XML-Schema document based on the schema tree extracted from original semistructured data. To ensure that semistructured data can be reconstructed from XML documents this transformation must be lossless. Finally the paper also presents an algorithm for reconstructing semistructured data.