Mediating RDF/S Queries to Relational and XML Sources

Koffina, Ioanna; Serfiotis, Giorgos; Christophides, Vassilis; Tannen, Val

doi:10.4018/978-1-60566-058-5.ch036

Cited by 6 publications

(7 citation statements)

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“…The vocab- Table 6: XML mapping. This table presents the features of transformation approaches, namely: existing vocabulary (yes -, no -), schema representation and level of automation (automatic -, semiautomatic -and manual -) Approaches Existing Schema Autovocabulary Representation matic [3] RDFS, DAML+OIL [10] RDFS, OWL [11] RDFS, OWL [13] n/a [14] RDFS, OWL [16,17] n/a [19] RDFS, OWL [40] RDFS, OWL [43] RDFS, OWL [55] RDFS, OWL [56] RDFS, OWL [57] n/a [60] n/a [62] RDFS, OWL [71] RDFS, OWL [73] RDFS, OWL [94] RDFS [95] RDFS [99] RDFS, OWL [113] RDFS, OWL [124] RDFS, OWL [126] RDFS, OWL [135] RDFS, OWL [142] RDFS, OWL [148,149] RDFS, OWL [154] n/a [161] RDFS [162] RDFS, OWL ulary generated in that proposal reflects the database semantics. The mappings are stored in an R 2 O [9] document.…”

Section: Bringing Relational Databases Into the Rdfmentioning

confidence: 99%

RDF 1.1: Knowledge Representation and Data Integration Language for the Web

Tomaszuk

Hyland-Wood

2020

Symmetry

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Resource Description Framework (RDF) can seen as a solution in today's landscape of knowledge representation research. An RDF language has symmetrical features because subjects and objects in triples can be interchangeably used. Moreover, the regularity and symmetry of the RDF language allow knowledge representation that is easily processed by machines, and because its structure is similar to natural languages, it is reasonably readable for people. RDF provides some useful features for generalized knowledge representation. Its distributed nature, due to its identifier grounding in IRIs, naturally scales to the size of the Web. However, its use is often hidden from view and is, therefore, one of the less well-known of the knowledge representation frameworks. Therefore, we summarise RDF v1.0 and v1.1 to broaden its audience within the knowledge representation community. This article reviews current approaches, tools, and applications for mapping from relational databases to RDF and from XML to RDF. We discuss RDF serializations, including formats with support for multiple graphs and we analyze RDF compression proposals. Finally, we present a summarized formal definition of RDF 1.1 that provides additional insights into the modeling of reification, blank nodes, and entailments. arXiv:2001.00432v1 [cs.DB] 2 Jan 2020 organizing information from different information sources. In particular, RDF can be seen as a general proposition language for the Web, which consolidates data from heterogeneous sources. It can provide interoperability between applications that exchange the data.Knowledge representation and data integration in the context of RDF is relevant for several reasons, including: promotes data exchange and interoperability; facilitates the reuse of available systems and tools; enables a fair comparison of Web systems by using benchmarks. In particular, this article shows how the RDF data model can be related to other models.The RDF language enables large portions of existing data to be processed and analyzed. This produces the need to develop the foundations of this language. This article addresses this challenge by developing an abstract model that is suitable to formalize and explain properties about the RDF data. We study the RDF data model, minimal and maximal representations, and show complexity bounds for the main problems. ContributionsWhen we examine the state of the RDF data model, we see evidence of trade-offs that occurred as various constituencies took part in the design process. Many of these trade-offs were never completely summarized in the RDF standards. Our article reviews a final state of RDF, and to identify areas where this data model is poorly understood. Our contributions are:1. to compare the RDF reification approaches, 2. to analyze the RDF 1.1 interpretations, entailments and their complexity, 3. to study the RDF blank nodes and their complexity, 4. to compare the various RDF data integration approaches, 5. to compare the RDF 1.1 serialization formats, including multiple graph syntaxes,...

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Section: Bringing Relational Databases Into the Rdfmentioning

confidence: 99%

RDF 1.1: Knowledge Representation and Data Integration Language for the Web

Tomaszuk

Hyland-Wood

2020

Symmetry

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“…In the present work, we assume that the mapping between the schemas of the Web Services and the schema of the knowledge base is given. The (semi) automatic creation of schema mappings has been addressed in a large corpus of works, e.g., [16,3,24]. Furthermore, we are not concerned with entity disambiguation and data fusion in this paper.…”

Section: Complementary Problemsmentioning

confidence: 99%

Active knowledge

Preda

Kasneci

Suchanek

et al. 2010

Proceedings of the 2010 ACM SIGMOD International Conference on Management of Data

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The proliferation of knowledge-sharing communities and the advances in information extraction have enabled the construction of large knowledge bases using the RDF data model to represent entities and relationships. However, as the Web and its latently embedded facts evolve, a knowledge base can never be complete and up-to-date. On the other hand, a rapidly increasing suite of Web services provide access to timely and high-quality information, but this is encapsulated by the service interface. We propose to leverage the information that could be dynamically obtained from Web services in order to enrich RDF knowledge bases on the fly whenever the knowledge base does not suffice to answer a user query.To this end, we develop a sound framework for appropriately generating queries to encapsulated Web services and efficient algorithms for query execution and result integration. The query generator composes sequences of function calls based on the available service interfaces. As Web service calls are expensive, our method aims to reduce the number of calls in order to retrieve results with sufficient recall. Our approach is fully implemented in a complete prototype system named ANGIE 1 . The user can query and browse the RDF knowledge base as if it already contained all the facts from the Web services. This data, however, is gathered and integrated on the fly, transparently to the user. We demonstrate the viability and efficiency of our approach in experiments based on real-life data provided by popular Web services.

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“…En revanche, la traduction d'une requête du schéma global en requêtes sur le schéma des sources demande un mécanisme de réécriture de requêtes complexe. Il existe des systèmes, tels SWIM (Koffina et al, 2006) adoptant une approche GLAV permettant de mettre en correspondance des éléments de l'ontologie avec des éléments de schémas de sources. Ces systèmes relèvent à la fois des approches GAV et LAV et tirent ainsi profit de leurs avantages respectifs.…”

Section: Travaux Prochesunclassified

Construction automatique d'adaptateurs guidée par une ontologie pour l'intégration de sources et de données XML

Reynaud¹,

Safar²

2009

Techniques et sciences informatiques

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Le travail décrit dans ce papier porte sur l'intégration de sources d'informations hétérogènes XML au sein d'un serveur d'information selon une approche mixte combinant médiation et entrepôt de données. Ce serveur dispose d'un schéma, ou ontologie, utilisé pour l'accès tant aux sources externes qu'aux données locales. La méthode que nous proposons est une méthode unifiée qui s'appuie sur l'ontologie et permet de réaliser à la fois l'intégration de sources et de données. Notre contribution est double. Elle porte d'une part sur la génération automatisée de mises en correspondance, ou mappings, entre l'ontologie et une nouvelle source à intégrer, d'autre part sur la construction automatique d'adaptateurs (wrappers en anglais) allant de la description du contenu abstrait de cette nouvelle source jusqu'à l'extraction des données. Des expérimentations ont été réalisées sur des données réelles dans le domaine du tourisme. ABSTRACT. This paper deals with integration of XML heterogeneous information sources into an information server according to an approach combining mediation and data warehousing. A schema, or ontology, is used to access to the external sources and also to the local data. We propose a unified method based on such an ontology able to achieve the two kinds of integration. Our contribution is twofold. First, we propose techniques to automate the generation of mappings between the ontology and a new source. Second, we present an approach to automate the construction of wrappers starting from the description of the abstract content of a source and ending by data extraction. Experiments on real data in the tourism domain have been achieved. Analysis and comments of the results are given.

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Mediating RDF/S Queries to Relational and XML Sources

Cited by 6 publications

References 0 publications

RDF 1.1: Knowledge Representation and Data Integration Language for the Web

RDF 1.1: Knowledge Representation and Data Integration Language for the Web

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Construction automatique d'adaptateurs guidée par une ontologie pour l'intégration de sources et de données XML

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