XML data integration with identification
Antonella Poggi, Serge Abiteboul · 2005
Abstract. Data integration is the problem of combining data residing at different sources, and providing the user with a virtual view, called global schema, independent from the sources. Our goal is to address some of the issues related to XML data integration. In particular, we highlight two major issues that emerge in this context: (i) the global schema may be characterized by a set of constraints, expressed by a DTD and XML integrity constraints, (ii) the concept of node identity requires to introduce semantic criteria to identify nodes coming from different sources. We propose a formal framework for XML data integration systems based on an expressive global schema, a set of XML data sources and a set of mappings specified by means of a simple tree language. Then, we define an identification function that aims at globally identifying nodes coming from different sources. Finally, we address query answering and propose algorithms to answer queries under different assumptions for the mappings. 1