Query rewriting is a fundamental task in query optimization and data integration. With the advent of the web, there has been renewed interest in data integration, where data is dis...
Xia Yang, Mong-Li Lee, Tok Wang Ling, Gillian Dobb...
An important direction in database research for non-standard applications (e.g. engineering or design applications) deals with adequate support for complex objects. Without doubt,...
Abstract. Semistructured data has no absolute schema xed in advance and its structure may be irregular or incomplete. Such data commonly arises in sources that do not impose a rigi...
In the study of data exchange one usually assumes an openworld semantics, making it possible to extend instances of target schemas. An alternative closed-world semantics only move...
The goal of this paper is to give an overview of the basics of the theory of RDF databases. We provide a formal definition of RDF that includes the features that distinguish this m...