Resource Description Framework (RDF) is a language which represents information about resources. In order to search RDF resource descriptions, several RDF query languages such as RQL and SquishQL have been proposed. However, these RDF query languages do not use XML syntax and they have limited functionality. xRQL is proposed to solve these issues by defining an XML-based RDF query language with...

Topic Maps and RDF are two independently developed paradigms and standards for the representation, interchange, and exploitation of model-based data on the web. Each paradigm has established its own user communities. Each of the standards allows data to be represented as a graph with nodes and labeled arcs which can be serialized in one or more XMLor SGML-based syntaxes. However, the two data m...

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 model from other graph data models. We then move into the fundamental issue of querying RDF data. We start by considering the RDF query language SPARQL, which is a W3C Recommendation since January 2008. We provide an a...

Privacy protection in published data sets is of crucial importance, and anonymisation is one well-known technique for privacy protection that has been successfully used in practice. However, existing anonymisation frameworks have in mind specific data structures (i.e., tabular data) and, because of this, these frameworks are difficult to apply in the case of RDF data. This paper presents an RDF...

Since the beginning of the Semantic Web, RDF and SPARQL have become the standard data model and query language to describe resources on the Web. Large amounts of RDF data are now available either as stand-alone datasets or as metadata over semistructured documents, typically XML. The ability to apply RDF annotations over XML data emphasizes the need to represent and query data and metadata simu...

Both Topic Maps and RDF are popular semantic web standards designed for machine processing of web documents. Since these representations were originally created for different purposes, they have conceptual differences in their data models, and therefore have different tools to parse, store, and query them. However, there are more tools to handle RDF data than those existing for Topic Maps. Our ...

The Resource Description Framework (RDF) is an interoperable data representation format suitable for interchange and integration of data, especially in Open Data contexts. However, RDF is also becoming increasingly attractive in scenarios involving sensitive data, where data protection is a major concern. At its core, RDF does not support any form of access control and current proposals for ext...

The basic data model for the Semantic Web is RDF. In this paper we address updates in RDF. It is known that the semantics of updates for data models becomes unclear when the model turns, even slightly, more general than a simple relational structure. Using the framework of KatsunoMendelzon, we define a semantics for updates in RDF. Particularly we explore the behavior of this semantics for the ...