Virtuoso questions

On april 25 2014 we had a knowledge session on VirtuosoVirtuoso (Universal server) Details virtuoso webinar on 25 april. This page contains the questions and answers.

See also: LinkedIn item: Vragen over Virtuoso voor kennisoverdracht LOD2

Attendants

  • Martin Kaltenböck (Semantic Web CompanySemantic Web Company (SWC) is a technology provider headquartered in Vienna (Austria). SWC supports organizations from all industrial sectors worldwide to improve their information management. Our core product PoolParty has outstanding capabilities to extract meaning from big data by making use of linked data technologies., LOD2 PUBLINK)
  • Hugh Williams (OpenLink Software)
  • Patrick van Kleef (OpenLink Software)
  • Gerard Persoon (PiLOD Platform,GerardPersoonBV)
  • Richard Nagelmaeker (PiLOD Platform, Ordina)
  • Pieter van Everdingen (PiLOD Wiki, OpenIncBij OpenInc kun je terecht voor Enterprise ICT en Data architectuur diensten. OpenInc begeleid organisaties bij het ontwikkelen van nieuwe producten en diensten met Linked Open Data (LOD) en Linked Enterprise Data (LED) en is partner van Platform Linked Data Nederland (PLDN). De eigenaar van OpenInc, Pieter van Everdingen, is een van de oprichters van de Smart Data Group.)
  • Rein van 't Veer (Digital Heritage)

Questions

How to show RDF resources when accessed by their own URI

What are the differences between the open source and the closed source version of VirtuosoVirtuoso (Universal server)?

Can you share your experiences with other projects that are working with the combination of Hadoop, VirtuosoVirtuoso (Universal server) and Elasticsearch, in environments with a lot of dataWeergave van een feit, begrip of aanwijzing, geschikt voor overdracht, interpretatie of verwerking door een persoon of apparaat?

  • Most implementation we come across in the Enterprise are using VirtuosoVirtuoso (Universal server) as the RDF Quad Store for indexing of Meta Data in conjunction with a combination of Hadoop, Elasticsearch, Lucense/Solr , Key Value (No-SQLStructured Query Language (SQL)) database and traditional relational databases.
  • Example Elsevier http://www.slideshare.net/ayagoda/elsevier-smart-content-ldr-sem-tech-2012-v4 Smart Content Linked Data Repository

Is the new LOD2 ETLExtraction, Transformation and Load (ETL) tool Unified Views an open source tool that can be used within the PiLOD platform to get Hadoop data into an VirtuosoVirtuoso (Universal server) environment?

  • Unified Views is open source and will be part for the final LOD2 StackThe LOD2 Stack has been renamed to the Linked Data Stack in 2014. The LOD2 Stack comprises a number of tools for managing the life-cycle of Linked Data. The life-cycle comprises in particular the stages: 1) Extraction of RDF from text, XML and SQL,2) Querying and Exploration using SPARQL, 3) Authoring of Linked Data using a Semantic Wiki, 4) Semi-automatic link discovery between Linked Data sources, 5) Knowledge-base Enrichment and Repair release https://grips.semantic-web.at/display/UDDOC/Introduction
  • There was a LOD2 Webinar on Unified Views earlier this month
  • Don’t see anything specifically about Hadoop support but I would imagine hadoopThe Apache Hadoop software library is a framework that allows for the distributed processing of large data sets across clusters of computers using simple programming models. It is designed to scale up from single servers to thousands of machines, each offering local computation and storage. Rather than rely on hardware to deliver high-availability, the library itself is designed to detect and handle failures at the application layer, so delivering a highly-available service on top of a cluster of computers, each of which may be prone to failures.The project includes these modules: 1) Hadoop Common: The common utilities that support the other Hadoop modules. 2) Hadoop Distributed File System (HDFS™): A distributed file system that provides high-throughput access to application data. 3) Hadoop YARN: A framework for job scheduling and cluster resource management. 4) Hadoop MapReduce: A YARN-based system for parallel processing of large data sets. jobs can be defined in its processing pipeline for invocation in processing data (large), which once processed and transformed to RDF can be store in VirtuosoVirtuoso (Universal server) as a support triple store in the LOD2 StackThe LOD2 Stack has been renamed to the Linked Data Stack in 2014. The LOD2 Stack comprises a number of tools for managing the life-cycle of Linked Data. The life-cycle comprises in particular the stages: 1) Extraction of RDF from text, XML and SQL,2) Querying and Exploration using SPARQL, 3) Authoring of Linked Data using a Semantic Wiki, 4) Semi-automatic link discovery between Linked Data sources, 5) Knowledge-base Enrichment and Repair

What are the typical use casesEen usecase in software engineering en systems engineering is een beschrijving van een gedrag van een systeem, dat reageert op een verzoek dat stamt van buiten het systeem. Met andere woorden, de use case beschrijft "wie" met het betreffende systeem "wat" kan doen (bron: Wikipedia). for VirtuosoVirtuoso (Universal server) Sponger? And what are the differences, pros and cons compared to other RDF middleware?

What are best practices to convert RDBMS data to RDF dataWeergave van een feit, begrip of aanwijzing, geschikt voor overdracht, interpretatie of verwerking door een persoon of apparaat?

  • VirtuosoVirtuoso (Universal server) RDF Linked Data Views http://virtuoso.openlinksw.com/dataspace/doc/dav/wiki/Main/VOSSQL2RDF
  • VirtuosoVirtuoso (Universal server) R2RMLR2RML is a language for expressing customized mappings from relational databases to RDF datasets. Such mappings provide the ability to view existing relational data in the RDF data model, expressed in a structure and target vocabulary of the mapping author's choice. R2RML mappings are themselves RDF graphs and written down in Turtle syntax. R2RML enables different types of mapping implementations. Processors could, for example, offer a virtual SPARQL endpoint over the mapped relational data, or generate RDF dumps, or offer a Linked Data interface. support http://virtuoso.openlinksw.com/dataspace/doc/dav/wiki/Main/VirtR2RML
  • D2R Server which is part of the LOD2 StackThe LOD2 Stack has been renamed to the Linked Data Stack in 2014. The LOD2 Stack comprises a number of tools for managing the life-cycle of Linked Data. The life-cycle comprises in particular the stages: 1) Extraction of RDF from text, XML and SQL,2) Querying and Exploration using SPARQL, 3) Authoring of Linked Data using a Semantic Wiki, 4) Semi-automatic link discovery between Linked Data sources, 5) Knowledge-base Enrichment and Repair http://lod2.eu/Project/D2R-Server.html
  • Hand crafted scripts/programs for mapping Relational Data to RDF Datasets
  • DB2Triples already being used by one of the PiLOD platform users https://github.com/antidot/db2triples/

What are the possibilities with Geodata in VirtuosoVirtuoso (Universal server) 7.1?

What are the known issues with Geo data support in VirtuosoVirtuoso (Universal server) 7.1 and what is the schedule and priority to resolve those issues?

  • GeoKnow ends in 1.5 years time so would expect to have full compliance by then, but hope to be well before that http://geoknow.eu

Which parties are also interested in Geo DataWeergave van een feit, begrip of aanwijzing, geschikt voor overdracht, interpretatie of verwerking door een persoon of apparaat?

How to store time related data (temporal) ?

What would be your reading recommendation for the VirtuosoVirtuoso (Universal server) documentation?

What are best practices to run the server?