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Questions tagged [virtuoso]

Virtuoso is a multi-model relational database management system for data represented as Relational Tables and/or RDF Property Graphs. It is also equipped with in-built middleware for conceptual data integration across heterogeneously shaped and disparately located data.

Virtuoso, (a/k/a OpenLink Virtuoso and the Virtuoso Universal Server) from OpenLink Software, is a high-performance and scalable native relational database management system (RDBMS) for data (relations) organized as tables and/or property graphs. In addition to its RDBMS functionality, it is also equipped with a middleware layer that enables conceptual data integration and web services deployment.

Virtuoso is the RDF DBMS behind live services such as DBpedia, Uniprot, Bio2RDF, the Linked Open Data Cloud Cache, and many other bubbles in the Linked Open Data Cloud.

Product-specific questions are often best raised to product-specific arenas. For Virtuoso, these include the OpenLink Community Forum, the Virtuoso Users mailing list, Open Source Edition GitHub-hosted project bug reports and other issues, confidential Support cases, etc.

Related tags :

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Querying local SPARQL endpoint is very slow

I have setup a local SPARQL endpoint with DBPedia database using Openlink Virtuoso through this guide. Then I tried to query my database through Python with the help of RDFLib and SPARQLWrapper. Problem is the time it take for a query (through…
hainam
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Jena Fuseki Vs Virtuoso

I am running same queries on Virtuoso and Jena Fuseki - A query on Virtuoso gave ResultRows=594890 while on Fuseki it gave the error of "page not responding". Also in many other cases, the fuseki could not execute the same queries which were done by…
Khan
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Library to connect node.js to virtuoso graph?

My first project using two different new technologies would be to implement some session management on node.js, storing the session & user data into a Virtuoso Datastore. It's exciting, because I'm an old school C# / Java developer used to MySQL /…
Herman Junge
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Wikidata import into virtuoso

I would like to load wikidata into virtuoso. After days of searching I was unable to find any tutorial or at least somebody that uses virtuoso to sparql query wikidata. I would not like to spend money on a server to load 50G+ data for nothing. Why…
FranMercaes
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Setup RDF ontology with Virtuoso

I've googled for last few hours searching for tutorials or guides about how to configure RDF store with virtuoso server (open source version). I have RDF file which was created with Protégé software. How can I add this file to virtuoso server and…
aumanets
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I want to setup dbpedia dataset locally

I want to setup DBpedia dataset locally, but I'm not sure how to do it. I have downloaded mappingbased_objects_en.ttl and infobox_properties_mapped_en.ttl.bz2, is there anything else I need to download, now how can I query this using SPARQL ? do I…
anandh perumal
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Get Wikidata entity descriptions via SPARQL, without Wikidata label service

I found this following code snippet on opendata.stackexchange.com, which returns name and description of citizens of the US from Wikidata: prefix wdt: prefix wd: PREFIX…
Yuehai
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unexpected behaviour with FILTER on xsd:date

How can I filter the count of a result (occurrences of strikes) to a particular year (1970)? My solution provides unexpected results. In the query I have written down alternatives I tried and their outcome. Solutions mentioned by others ([1], [2])…
Richard
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User-defined SPARQL aggregation functions in Virtuoso

I want to implement a user-defined boolean aggregation function in SPARQL and I am checking whether how easy/feasible is this in different SPARQL engines. In regards to Virtuoso, is it possible? If so, where could I find further information about…
Luis Galárraga
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Complex SPARQL query - Virtuoso performance hints?

I have a rather complex SPARQL query, which is executed thousands of times in parallel threads (400 threads). The query is here somewhat simplified (namespaces, properties, and variables have been reduced) for readability, but the complexity is left…
Pantelis Natsiavas
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Protege sees relationship, Virtuoso doesn't

Viewing the go-plus ontology in a freshly installed, stock Protégé 5, I found a useful inference in the entities tab for http://purl.obolibrary.org/obo/GO_0003215: 'cardiac right ventricle morphogenesis' 'results in morphogenesis of' some 'cardiac…
Mark Miller
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Virtuoso Large RDF Graph Removal Difficulty

I am using Virtuoso. It is installed on a server machine. I am trying to remove a large RDF graph from my Virtuoso. It contains 2,590,994,053 triples. I was trying to delete the graph with the following command. SPARQL DROP SILENT GRAPH…
Beautiful Mind
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Double values are truncated (rounded) in Virtuoso SRARQL results

I am using Virtuoso Opensource 7.2.4 and have a dataset which consists of some data, for example: @prefix xsd: @prefix geo: . @prefix ap:…
Nandana
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What is the proper universal way of inserting blank nodes using SPARQL

I am writing an application using the Apache Jena framework. With this I am able to do everything (insert, update, select). But i can't wrap my head around how to properly insert blank nodes using an INSERT query. Is there a go-to approach for this…
oole
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For GROUP_CONCAT, "\n" is interpreted as space

I'd like to have each of the concatenated results in a new line (results format HTML). I use something like that: (Group_Concat(DISTINCT ?result; separator = '\n ') as ?results) However, both \n and \r are interpreted as space, while using any…
Ivo Velitchkov
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