The continuous accumulation of multi-dimensional data and the development Semantic Web Linked Data published in Resource Description Framework (RDF) bring new requirements for analytics tools. Such tools should take into account special features RDF graphs, exploit semantics support flexible aggregate queries. In this paper, we present an approach applying to based on a high-level functional qu...

As more and more data is provided in RDF format, storing huge amounts of RDF data and efficiently processing queries on such data is becoming increasingly important. The first part of the lecture will introduce state-of-the-art techniques for scalably storing and querying RDF with relational systems, including alternatives for storing RDF, efficient index structures, and query optimization tech...

RDF, graph isomorphism, equality The Resource Description Framework (RDF) describes graphs of statements about resources. This paper explores the equality of two RDF graphs in light of the graph isomorphism literature. We consider anonymous resources as unlabelled vertices in a graph, and show that the standard graph isomorphism algorithms, developed in the 1970's, can be used effectively for c...

This paper presents inference rules for Resource Description Framework (RDF), RDF Schema (RDFS) and Web Ontology Language (OWL). Our formalization is based on Notation 3 Logic, which extended RDF by logical symbols and created Semantic Web logic for deductive RDF graph stores. We also propose OWL-P that is a lightweight formalism of OWL and supports soft inferences by omitting complex language ...

RDF and RDF Schema are two W3C standards aimed at enriching the Web with machine-processable semantic data. We have developed Sesame, an architecture for efficient storage and expressive querying of large quantities of metadata in RDF and RDF Schema. Sesame’s design and implementation are independent from any specific storage device. Thus, Sesame can be deployed on top of a variety of storage d...

In this paper, we provide a survey on the models and query languages for temporally annotated RDF. In most of the works, a temporally annotated RDF ontology is essentially a set of RDF triples associated with temporal constraints, where, in the simplest case, a temporal constraint is a validity temporal interval. However, a temporally annotated RDF ontology may also be a set of triples connecti...

The Linked Data standard — which is based on the publication of data in the Web as RDF triples — is gaining increasing attention as a way to promote open data interoperability. The publication of data originally stored in relational databases as RDF is known as the RDB-to-RDF approach. The first step in this process requires the mapping of database concepts to RDF vocabularies, used as the base...