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We present a query language called GraphLog, based on a graph representation of both data and queries. Queries are graph patterns. Edges in queries represent edges or paths in the database. Regular expressions are used to qualify these paths. We characterize the expressive power of the language and show that it is equivalent to stratified linear Datalog,(More)
The Linked Movie Database (LinkedMDB) project provides a demonstration of the first open linked dataset connecting several major existing (and highly popular) movie web resources. The database exposed by LinkedMDB contains millions of RDF triples with hundreds of thousands of RDF links to existing web data sources that are part of the growing Linking Open(More)
GraphLog is a visual query language in which queries are formulated by drawing graph patterns. The hyperdocument graph is searched for all occurrences of these patterns. The language is powerful enough to allow the specification and manipulation of arbitrary subsets of the network and supports the computation of aggregate functions on subgraphs of the(More)
There is a signiicant amount of interest in combining and extending database and information retrieval technologies to manage textual data. The challenge is becoming more relevant due to increased availability of documents in digital form. Document data has a natural hierarchical structure, which may be made explicit due to the use of markup conventions (as(More)
The W3C XQuery language recommendation, based on a hierarchical and ordered document model, supports a wide variety of constructs and use cases. There is a diversity of approaches and strategies for evaluating XQuery expressions, in many cases only dealing with limited subsets of the language. In this paper we describe an implementation approach that(More)
This paper presents database applications of the recently proposed Transaction Logic|an extension of classical predicate logic that accounts in a clean and declarative fashion for the phenomenon of state changes in logic programs and databases. It has a natural model theory and a sound and complete proof theory, but, unlike many other logics, it allows(More)
strat evalu se of nd re mon ement pported. In additio he speedups obtained using summaries with those reported for index-b w z ef Lan fo o anipulat XML documents. XQuery and its widely adopted Path r a d im /SQRL [13], ToX .g. Galax [20]) and work that addresses certain aspects of XQuery processing such as XPath, twig queries and index structures for XML(More)
Learning Objectives: Tutorial attendees will learn about requirements for combined DB and IR applications that access XML content; learn about models and indexes tailored to XML and their algorithms; understand the specific problems of XML IR and XML query processing; learn about XML retrieval evaluation, INEX in particular; learn about the challenges in(More)
The Linking Open Data community project is extending the Web by encouraging the creation of interlinks (RDF links between data items from different datasets identified using dereferenceable URIs). This emerging Web of linked data is closely intertwined with the existing Web, since structured data items can be embedded into Web documents (e.g., RDFa or(More)