# EU Cellar Virtuoso Semantic Repository Use Case

HTML: [eu-cellar-virtuoso-semantic-repository-usecase-gpt5-chat-1.html](eu-cellar-virtuoso-semantic-repository-usecase-gpt5-chat-1.html)  
RDF Turtle: [eu-cellar-virtuoso-semantic-repository-usecase-gpt5-chat-1.ttl](../rdf/eu-cellar-virtuoso-semantic-repository-usecase-gpt5-chat-1.ttl)  
JSON-LD: [eu-cellar-virtuoso-semantic-repository-usecase-gpt5-chat-1.jsonld](../rdf/eu-cellar-virtuoso-semantic-repository-usecase-gpt5-chat-1.jsonld)

## Overview

This Markdown companion mirrors the RDF-backed HTML use-case analysis of [Virtuoso](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fdbpedia.org%2Fresource%2FVirtuoso_Universal_Server) as the RDF triple-store, SPARQL platform, Linked Data substrate, and scalable runtime behind the [Cellar Knowledge Graph](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23cellarKnowledgeGraph). It treats Cellar as a public-sector semantic repository pattern: many harvested EU open datasets, RDF metadata, durable IRIs, CDM/WEMI modeling, REST for known content retrieval, SPARQL for graph discovery, 24/7 access for humans and [AI agents](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23humanAndAgentAccess), and Cello-style assistant templates for user-facing query workflows.

## Use-Case Frame

- [European Union Cellar Virtuoso Use Case](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23cellarProject): Case study of Cellar as a Virtuoso-backed semantic repository operated by the Publications Office of the European Union using Linked Data principles.
- [Cellar Knowledge Graph](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23cellarKnowledgeGraph): EU publication metadata knowledge graph constructed from many EU open datasets, stored in a triple store, and queried using SPARQL.
- [EU open data harvesting](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23euOpenDataHarvesting): Cellar-scale knowledge graph construction depends on harvesting and harmonizing open datasets from across the European Union.
- [DBpedia Knowledge Graph](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fdbpedia.org%2Fresource%2FDBpedia): 24/7 public knowledge graph powered by Virtuoso, used here as a comparison point for Cellar-style open data access.
- [Linked Data principles](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fdbpedia.org%2Fresource%2FLinked_data): Use HTTP IRIs, publish RDF descriptions, and connect resources so Cellar manifests a navigable Semantic Web.
- [Semantic Web](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fdbpedia.org%2Fresource%2FSemantic_Web): Web of machine-readable RDF resources enabled when public knowledge graphs expose dereferenceable identifiers and typed links.
- [Human and AI agent access](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23humanAndAgentAccess): The deployed graph must be usable by browsers, SPARQL tools, applications, and AI agents that need durable identifiers and machine-readable context.
- [24/7 knowledge graph availability](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23twentyFourSevenAvailability): Public-sector knowledge graphs need continuous availability for institutional users, citizens, developers, and automated agents.
- [High performance and scalability](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23highPerformanceScalability): High-performance SPARQL execution, large graph scale, concurrency, and reliable uptime are non-negotiable platform requirements.
- [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this): Public SPARQL interface for querying Cellar metadata.
- [Virtuoso Universal Server](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fdbpedia.org%2Fresource%2FVirtuoso_Universal_Server): Virtuoso triple store/SPARQL platform identified in Cellar training as the Cellar knowledge graph store.
- [Cello Assistant](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fgithub.com%2FOpenLinkSoftware%2FAssistants%2Fblob%2Fmain%2Fcello-config.md%23this): OpenLink assistant that uses AI and SPARQL templates to query the Cellar Public Knowledge Graph.
- [Common Data Model Ontology](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23this): Cellar ontology used to describe EU publications and query metadata.
- [FRBR WEMI Model](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fdbpedia.org%2Fresource%2FFunctional_Requirements_for_Bibliographic_Records): Work, Expression, Manifestation, and Item hierarchy used to model publications.
- [Cellar REST API](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fresource%2F%23this): REST interface for retrieving Cellar content streams and metadata notices.
- [European Data Portal SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fdata.europa.eu%2Fdata%2Fsparql%23this): SPARQL endpoint for the European Data Portal, included for linked data context.

## Platform Pattern

- [Use-case problem](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23usecaseProblem): EU publications require multilingual, persistent, queryable metadata across legal, bibliographic, vocabulary, organisational, and harvested open-data domains.
- [EU open-data harvesting pattern](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23usecaseHarvesting): Cellar represents a pattern for turning many EU datasets into a coherent RDF knowledge graph that remains available around the clock.
- [Linked Data deployment pattern](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23usecaseSemanticWebDeployment): The graph has to be deployed using Linked Data principles: durable IRIs, RDF descriptions, typed links, and resolver-friendly access that materialize a Semantic Web.
- [Performance and scalability mandate](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23usecasePerformanceScalability): The platform choice must satisfy non-negotiable requirements for graph scale, SPARQL performance, uptime, and concurrent human and agent access.
- [Virtuoso role](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23usecaseVirtuosoRole): Virtuoso provides the RDF triple-store, SPARQL access layer, Linked Data publishing substrate, and scalable runtime for Cellar metadata workloads.
- [SPARQL workloads](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23usecaseWorkloads): Representative workloads include WEMI traversal, Official Journal retrieval, Whoiswho organisation lookup, identifier resolution, and assistant-mediated templates.
- [Integration pattern](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23usecaseIntegration): Cellar combines REST for known content retrieval, feeds for ingestion notifications, and SPARQL for discovery, relationship traversal, and metadata analytics.
- [Use-case outcomes](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23usecaseOutcomes): The Virtuoso-backed Cellar pattern enables machine-readable EU publication metadata, reusable identifiers, queryable vocabularies, assistant-mediated access, and public Semantic Web deployment.
- [Implementation considerations](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23usecaseRisks): The use case depends on durable IRIs, clear endpoint/query guidance, vocabulary literacy, query templates, careful asserted-versus-inferred metadata handling, and tested scale characteristics.

## Sources

- [About the Cellar Knowledge Graph](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2Fcellar-data%2Fmetadata%2Fknowledge-graph): [source](https://op.europa.eu/en/web/cellar/cellar-data/metadata/knowledge-graph)
- [Architecture - Cellar](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2Farchitecture): [source](https://op.europa.eu/en/web/cellar/architecture)
- [Cellar Documentation](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2Fdocumentation): [source](https://op.europa.eu/en/web/cellar/documentation)
- [Cellar SPARQL Training, EU Learn Part 2](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fdocuments%2Fd%2Fcellar%2F2025_cellar_sparql_training_eulearn-part2): [source](https://op.europa.eu/documents/d/cellar/2025_cellar_sparql_training_eulearn-part2)
- [Cellar: The semantic repository of the Publications Office](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fpublication-detail%2F-%2Fpublication%2F50ecce27-857e-11e8-ac6a-01aa75ed71a1%2Flanguage-en): [source](https://op.europa.eu/en/publication-detail/-/publication/50ecce27-857e-11e8-ac6a-01aa75ed71a1/language-en)
- [Publications Organisation Structure Chart](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fdocuments%2F10530%2F8583568%2FOrgChartViewer_OP_EN_01-05-2022.pdf%2F): [source](https://op.europa.eu/documents/10530/8583568/OrgChartViewer_OP_EN_01-05-2022.pdf/)
- [Cello Assistant Demo](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fgithub.com%2FOpenLinkSoftware%2FAssistants%2Fblob%2Fmain%2Fcello-config.md): [source](https://github.com/OpenLinkSoftware/Assistants/blob/main/cello-config.md)
- [CELLAR Virtuoso SPARQL endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql): [source](http://publications.europa.eu/webapi/rdf/sparql)
- [European Data Portal SPARQL Service Endpoint](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fdata.europa.eu%2Fdata%2Fsparql): [source](https://data.europa.eu/data/sparql)

## SPARQL Query Examples

### [Extract a WEMI hierarchy](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryExtractWemiHierarchy)

Retrieves Work, Expression, Manifestation, Item, language code, and format for a CELEX identifier.

Target endpoint: [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this)

Live query: [Run live query](http://publications.europa.eu/webapi/rdf/sparql?default-graph-uri=&query=prefix%20cdm%3A%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23%3E%0Aprefix%20owl%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2002%2F07%2Fowl%23%3E%0Aprefix%20purl%3A%20%3Chttp%3A%2F%2Fpurl.org%2Fdc%2Felements%2F1.1%2F%3E%0Aselect%20distinct%20%3Fwork%2C%20%3Fexpr%2C%20%3Fmanif%2C%20%3FlangCode%2C%20str(%3Fformat)%20as%20%3Fformat%2C%20%3Fitem%0Awhere%20%7B%0A%20%20%3Fwork%20owl%3AsameAs%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fresource%2Fcelex%2F32018R1805%3E%20.%0A%20%20%3Fexpr%20cdm%3Aexpression_belongs_to_work%20%3Fwork%20%3B%0A%20%20%20%20%20%20%20%20cdm%3Aexpression_uses_language%20%3Flang%20.%0A%20%20%3Flang%20purl%3Aidentifier%20%3FlangCode%20.%0A%20%20%3Fmanif%20cdm%3Amanifestation_manifests_expression%20%3Fexpr%3B%0A%20%20%20%20%20%20%20%20%20cdm%3Amanifestation_type%20%3Fformat.%0A%20%20%3Fitem%20cdm%3Aitem_belongs_to_manifestation%20%3Fmanif.%0A%7D%20LIMIT%201000&format=text%2Fhtml&timeout=0&debug=on&run=+Run+Query+)

```sparql
prefix cdm: <http://publications.europa.eu/ontology/cdm#>
prefix owl: <http://www.w3.org/2002/07/owl#>
prefix purl: <http://purl.org/dc/elements/1.1/>
select distinct ?work, ?expr, ?manif, ?langCode, str(?format) as ?format, ?item
where {
  ?work owl:sameAs <http://publications.europa.eu/resource/celex/32018R1805> .
  ?expr cdm:expression_belongs_to_work ?work ;
        cdm:expression_uses_language ?lang .
  ?lang purl:identifier ?langCode .
  ?manif cdm:manifestation_manifests_expression ?expr;
         cdm:manifestation_type ?format.
  ?item cdm:item_belongs_to_manifestation ?manif.
} LIMIT 1000
```

### [Retrieve Official Journals published in 2022](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryOfficialJournals2022)

Finds Official Journal resources from 2022 and their business identifiers.

Target endpoint: [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this)

Live query: [Run live query](http://publications.europa.eu/webapi/rdf/sparql?default-graph-uri=&query=prefix%20cdm%3A%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23%3E%0Aprefix%20owl%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2002%2F07%2Fowl%23%3E%0Aprefix%20rdf%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F1999%2F02%2F22-rdf-syntax-ns%23%3E%0Aprefix%20xsd%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2001%2FXMLSchema%23%3E%0ASELECT%20%3Furi%20%3FbusinessIdentifier%0AWHERE%20%7B%0A%20%20%3Furi%20cdm%3Aofficial-journal_year%20%222022%22%5E%5Exsd%3AgYear.%0A%20%20%3Furi%20rdf%3Atype%20cdm%3Aofficial-journal.%0A%20%20%3Furi%20owl%3AsameAs%20%3FbusinessIdentifier%20.%0A%7D&format=text%2Fhtml&timeout=0&debug=on&run=+Run+Query+)

```sparql
prefix cdm: <http://publications.europa.eu/ontology/cdm#>
prefix owl: <http://www.w3.org/2002/07/owl#>
prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
prefix xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT ?uri ?businessIdentifier
WHERE {
  ?uri cdm:official-journal_year "2022"^^xsd:gYear.
  ?uri rdf:type cdm:official-journal.
  ?uri owl:sameAs ?businessIdentifier .
}
```

### [Retrieve EU Whoiswho data](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryEuWhoiswho)

Retrieves person, membership, position, and organisation labels from the EU Whoiswho branch.

Target endpoint: [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this)

Live query: [Run live query](http://publications.europa.eu/webapi/rdf/sparql?default-graph-uri=&query=prefix%20skos%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2004%2F02%2Fskos%2Fcore%23%3E%0Aprefix%20foaf%3A%20%3Chttp%3A%2F%2Fxmlns.com%2Ffoaf%2F0.1%2F%3E%0Aprefix%20euvoc%3A%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fontology%2Feuvoc%23%3E%0Aprefix%20org%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2Fns%2Forg%23%3E%0Aprefix%20vcard%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2006%2Fvcard%2Fns%23%3E%0Aprefix%20person%3A%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fresource%2Fperson%3E%0ASELECT%20DISTINCT%20*%0Awhere%20%7B%0A%20%20%3Fper%20a%20foaf%3APerson.%20%3Fper%20foaf%3Aname%20%3Fname%20.%0A%20%20%3Fper%20foaf%3AgivenName%20%3FgivenName%20.%0A%20%20%3Fper%20vcard%3AhasGender%20%3Fgender%20.%0A%20%20%3Fper%20foaf%3AfamilyName%20%3FfamilyName%20.%0A%20%20%3Fper%20org%3AhasMembership%20%3Fmembership.%0A%20%20%3Fper%20vcard%3AhasHonorificPrefix%20%3FhonorificPrefix%20.%0A%20%20%3Fmembership%20euvoc%3ApositionComplement%20%3Fposition%20.%0A%20%20%3Fmembership%20org%3Aorganization%20%3Forg%20.%0A%20%20%3Forg%20skos%3AprefLabel%20%3Flabel%20.%0A%20%20FILTER%20(str(%3FfamilyName)%20%3D%20'MICHEL'%20%26%26%20str(%3FgivenName)%20%3D%20'Charles')%0A%20%20FILTER%20(lang(%3Fposition)%20%3D%20'en'%20%26%26%20lang(%3Flabel)%20%3D%20'en')%0A%7D&format=text%2Fhtml&timeout=0&debug=on&run=+Run+Query+)

```sparql
prefix skos: <http://www.w3.org/2004/02/skos/core#>
prefix foaf: <http://xmlns.com/foaf/0.1/>
prefix euvoc: <http://publications.europa.eu/ontology/euvoc#>
prefix org: <http://www.w3.org/ns/org#>
prefix vcard: <http://www.w3.org/2006/vcard/ns#>
prefix person: <http://publications.europa.eu/resource/person>
SELECT DISTINCT *
where {
  ?per a foaf:Person. ?per foaf:name ?name .
  ?per foaf:givenName ?givenName .
  ?per vcard:hasGender ?gender .
  ?per foaf:familyName ?familyName .
  ?per org:hasMembership ?membership.
  ?per vcard:hasHonorificPrefix ?honorificPrefix .
  ?membership euvoc:positionComplement ?position .
  ?membership org:organization ?org .
  ?org skos:prefLabel ?label .
  FILTER (str(?familyName) = 'MICHEL' && str(?givenName) = 'Charles')
  FILTER (lang(?position) = 'en' && lang(?label) = 'en')
}
```

### [Cello template: publications about a subject](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryCelloPublicationsBySubject)

Cello assistant template that federates into Cellar and matches EuroVoc labels.

Target endpoint: [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this)

Live query: template requires value substitution before execution.

```sparql
PREFIX cdm: <http://publications.europa.eu/ontology/cdm#>
PREFIX skos-core: <http://www.w3.org/2004/02/skos/core#>
SELECT *
WHERE {
  SERVICE <https://publications.europa.eu/webapi/rdf/sparql> {
    SELECT DISTINCT ?work ?label
    WHERE {
      ?work cdm:resource_legal_in-force "1"^^<http://www.w3.org/2001/XMLSchema#boolean> ;
            a cdm:legislation_secondary;
            cdm:work_date_document ?date ;
            cdm:work_is_about_concept_eurovoc ?eurovoc .
      {
        SELECT ?eurovoc
        WHERE {
          ?eurovoc skos-core:inScheme <http://eurovoc.europa.eu/100141>;
                   skos-core:prefLabel ?label .
          FILTER (str(?label)="{{Subject}}")
        }
      }
    }
    ORDER BY DESC(?date)
  }
}
{{LIMIT provided by /limit value. Default is LIMIT 10.}}
```

### [Cello template: business identifiers, title, and date](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryCelloBusinessIdentifiers)

Cello assistant template for resolving identifiers and publication titles through CDM.

Target endpoint: [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this)

Live query: template requires value substitution before execution.

```sparql
PREFIX cdm: <http://publications.europa.eu/ontology/cdm#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
SELECT *
WHERE {
  SERVICE <https://publications.europa.eu/webapi/rdf/sparql> {
    SELECT GROUP_CONCAT(?psi, ',') AS ?identifier, STR(?title) AS ?title, ?date
    WHERE {
      ?expression cdm:expression_belongs_to_work ?work.
      ?work owl:sameAs ?psi .
      ?work cdm:work_date_document ?date .
      ?expression cdm:expression_title ?title.
      ?expression cdm:expression_uses_language <http://publications.europa.eu/resource/authority/language/ENG>.
      OPTIONAL { ?expression cdm:expression_subtitle ?subtitle. }
      VALUES(?work) { (<{{Add Publication URI Here}}>) }
    }
  }
}
{{LIMIT provided by /limit value. Default is LIMIT 10.}}
```

### [Training example: inspect triples for a Cellar identifier](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryInspectCellarTriples)

Training-deck example that lists predicate/object pairs for a known Cellar resource.

Target endpoint: [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this)

Live query: [Run live query](http://publications.europa.eu/webapi/rdf/sparql?default-graph-uri=&query=prefix%20cellar%3A%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fresource%2Fcellar%2F%3E%0Aselect%20%3Fproperty%20%3Fobject%0Awhere%20%7B%0A%20%20cellar%3Adb594e8d-c430-11ec-b6f4-01aa75ed71a1%20%3Fproperty%20%3Fobject%20.%0A%7D&format=text%2Fhtml&timeout=0&debug=on&run=+Run+Query+)

```sparql
prefix cellar: <http://publications.europa.eu/resource/cellar/>
select ?property ?object
where {
  cellar:db594e8d-c430-11ec-b6f4-01aa75ed71a1 ?property ?object .
}
```

### [Training example: retrieve other identifiers of a publication](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryPublicationOtherIdentifiers)

Training-deck example that starts from an Official Journal business identifier and retrieves equivalent publication identifiers.

Target endpoint: [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this)

Live query: [Run live query](http://publications.europa.eu/webapi/rdf/sparql?default-graph-uri=&query=prefix%20owl%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2002%2F07%2Fowl%23%3E%0ASELECT%20%3Furi%20%3Fpsi%0AWHERE%20%7B%0A%20%20%3Furi%20owl%3AsameAs%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fresource%2Foj%2FJOC_2022_182_R_0001%3E.%0A%20%20%3Furi%20owl%3AsameAs%20%3Fpsi.%0A%7D&format=text%2Fhtml&timeout=0&debug=on&run=+Run+Query+)

```sparql
prefix owl: <http://www.w3.org/2002/07/owl#>
SELECT ?uri ?psi
WHERE {
  ?uri owl:sameAs <http://publications.europa.eu/resource/oj/JOC_2022_182_R_0001>.
  ?uri owl:sameAs ?psi.
}
```

### [Training example: retrieve languages and formats](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryPublicationLanguagesFormats)

Training-deck example that traverses Work, Expression, Manifestation, and Item resources to list language labels and formats.

Target endpoint: [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this)

Live query: [Run live query](http://publications.europa.eu/webapi/rdf/sparql?default-graph-uri=&query=prefix%20cdm%3A%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23%3E%0Aprefix%20owl%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2002%2F07%2Fowl%23%3E%0Aprefix%20skos%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2004%2F02%2Fskos%2Fcore%23%3E%0ASELECT%20%3Flang_en%20%3Fformat%0AWHERE%20%7B%0A%20%20%3Fwork%20owl%3AsameAs%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fresource%2Foj%2FJOC_2022_182_R_0001%3E.%0A%20%20%3Fexpression%20cdm%3Aexpression_belongs_to_work%20%3Fwork.%0A%20%20%3Fmanifestation%20cdm%3Amanifestation_manifests_expression%20%3Fexpression.%0A%20%20%3Fitem%20cdm%3Aitem_belongs_to_manifestation%20%3Fmanifestation.%0A%20%20%3Fexpression%20cdm%3Aexpression_uses_language%20%3FlanguageConcept.%0A%20%20%3FlanguageConcept%20skos%3AprefLabel%20%3Flang_en.%0A%20%20FILTER(LANG(%3Flang_en)%3D%22en%22)%0A%20%20%3Fmanifestation%20cdm%3Amanifestation_type%20%3Fformat.%0A%7D&format=text%2Fhtml&timeout=0&debug=on&run=+Run+Query+)

```sparql
prefix cdm: <http://publications.europa.eu/ontology/cdm#>
prefix owl: <http://www.w3.org/2002/07/owl#>
prefix skos: <http://www.w3.org/2004/02/skos/core#>
SELECT ?lang_en ?format
WHERE {
  ?work owl:sameAs <http://publications.europa.eu/resource/oj/JOC_2022_182_R_0001>.
  ?expression cdm:expression_belongs_to_work ?work.
  ?manifestation cdm:manifestation_manifests_expression ?expression.
  ?item cdm:item_belongs_to_manifestation ?manifestation.
  ?expression cdm:expression_uses_language ?languageConcept.
  ?languageConcept skos:prefLabel ?lang_en.
  FILTER(LANG(?lang_en)="en")
  ?manifestation cdm:manifestation_type ?format.
}
```

### [Training example: retrieve all work metadata](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryWorkMetadata)

Training-deck example that retrieves all direct predicate/object metadata attached to the normalized work resource.

Target endpoint: [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this)

Live query: [Run live query](http://publications.europa.eu/webapi/rdf/sparql?default-graph-uri=&query=prefix%20owl%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2002%2F07%2Fowl%23%3E%0ASELECT%20%3Fwork%20%3Fp%20%3Fo%0AWHERE%20%7B%0A%20%20%3Fwork%20owl%3AsameAs%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fresource%2Foj%2FJOC_2022_182_R_0001%3E.%0A%20%20%3Fwork%20%3Fp%20%3Fo.%0A%7D&format=text%2Fhtml&timeout=0&debug=on&run=+Run+Query+)

```sparql
prefix owl: <http://www.w3.org/2002/07/owl#>
SELECT ?work ?p ?o
WHERE {
  ?work owl:sameAs <http://publications.europa.eu/resource/oj/JOC_2022_182_R_0001>.
  ?work ?p ?o.
}
```

### [Training example: retrieve publication metadata across WEMI](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryPublicationMetadataWemi)

Training-deck example that retrieves metadata across Work, Expression, Manifestation, and Item levels.

Target endpoint: [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this)

Live query: [Run live query](http://publications.europa.eu/webapi/rdf/sparql?default-graph-uri=&query=prefix%20cdm%3A%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23%3E%0Aprefix%20owl%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2002%2F07%2Fowl%23%3E%0ASELECT%20%3Fwork%20%3FpWork%20%3FoWork%20%3Fexpression%20%3FpExpression%20%3FoExpression%20%3Fmanifestation%20%3FpManifestation%20%3FoManifestation%20%3Fitem%20%3FpItem%20%3FoItem%0AWHERE%20%7B%0A%20%20%3Fwork%20owl%3AsameAs%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fresource%2Foj%2FJOC_2022_182_R_0001%3E.%0A%20%20%3Fexpression%20cdm%3Aexpression_belongs_to_work%20%3Fwork.%0A%20%20%3Fmanifestation%20cdm%3Amanifestation_manifests_expression%20%3Fexpression.%0A%20%20%3Fitem%20cdm%3Aitem_belongs_to_manifestation%20%3Fmanifestation.%0A%20%20%3Fwork%20%3FpWork%20%3FoWork.%0A%20%20%3Fexpression%20%3FpExpression%20%3FoExpression.%0A%20%20%3Fmanifestation%20%3FpManifestation%20%3FoManifestation.%0A%20%20%3Fitem%20%3FpItem%20%3FoItem.%0A%7D%0Alimit%201000&format=text%2Fhtml&timeout=0&debug=on&run=+Run+Query+)

```sparql
prefix cdm: <http://publications.europa.eu/ontology/cdm#>
prefix owl: <http://www.w3.org/2002/07/owl#>
SELECT ?work ?pWork ?oWork ?expression ?pExpression ?oExpression ?manifestation ?pManifestation ?oManifestation ?item ?pItem ?oItem
WHERE {
  ?work owl:sameAs <http://publications.europa.eu/resource/oj/JOC_2022_182_R_0001>.
  ?expression cdm:expression_belongs_to_work ?work.
  ?manifestation cdm:manifestation_manifests_expression ?expression.
  ?item cdm:item_belongs_to_manifestation ?manifestation.
  ?work ?pWork ?oWork.
  ?expression ?pExpression ?oExpression.
  ?manifestation ?pManifestation ?oManifestation.
  ?item ?pItem ?oItem.
}
limit 1000
```

### [Training example: retrieve Official Journals in a date range](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryOfficialJournalsDateRange)

Training-deck example that retrieves Official Journals published within a specific period with class, number, collection, year, and document date.

Target endpoint: [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this)

Live query: [Run live query](http://publications.europa.eu/webapi/rdf/sparql?default-graph-uri=&query=prefix%20cdm%3A%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23%3E%0Aprefix%20rdf%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F1999%2F02%2F22-rdf-syntax-ns%23%3E%0Aprefix%20xsd%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2001%2FXMLSchema%23%3E%0ASELECT%20%3Furi%20%3Fojclass%20%3Fojnumber%20%3Fojcollection%20%3Fojyear%20%3Fworkdatedoc%0AWHERE%20%7B%0A%20%20%3Furi%20cdm%3Aofficial-journal_class%20%3Fojclass.%0A%20%20%3Furi%20cdm%3Aofficial-journal_number%20%3Fojnumber.%0A%20%20%3Furi%20cdm%3Aofficial-journal_part_of_collection_document%20%3Fojcollection.%0A%20%20%3Furi%20cdm%3Aofficial-journal_year%20%3Fojyear.%0A%20%20%3Furi%20cdm%3Awork_date_document%20%3Fworkdatedoc.%0A%20%20%3Furi%20rdf%3Atype%20cdm%3Aofficial-journal.%0A%20%20FILTER(%3Fworkdatedoc%20%3E%3D%20%222022-01-01%22%5E%5Exsd%3Adate%20%26%26%20%3Fworkdatedoc%20%3C%20%222022-10-01%22%5E%5Exsd%3Adate)%0A%7D&format=text%2Fhtml&timeout=0&debug=on&run=+Run+Query+)

```sparql
prefix cdm: <http://publications.europa.eu/ontology/cdm#>
prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
prefix xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT ?uri ?ojclass ?ojnumber ?ojcollection ?ojyear ?workdatedoc
WHERE {
  ?uri cdm:official-journal_class ?ojclass.
  ?uri cdm:official-journal_number ?ojnumber.
  ?uri cdm:official-journal_part_of_collection_document ?ojcollection.
  ?uri cdm:official-journal_year ?ojyear.
  ?uri cdm:work_date_document ?workdatedoc.
  ?uri rdf:type cdm:official-journal.
  FILTER(?workdatedoc >= "2022-01-01"^^xsd:date && ?workdatedoc < "2022-10-01"^^xsd:date)
}
```

### [Training example: retrieve Official Journal acts for 2024](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryOfficialJournalActs2024)

Training-deck example for the Official Journal act class introduced in the 2024 context.

Target endpoint: [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this)

Live query: [Run live query](http://publications.europa.eu/webapi/rdf/sparql?default-graph-uri=&query=prefix%20cdm%3A%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23%3E%0Aprefix%20rdf%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F1999%2F02%2F22-rdf-syntax-ns%23%3E%0Aprefix%20xsd%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2001%2FXMLSchema%23%3E%0ASELECT%20%3Furi%0AWHERE%20%7B%0A%20%20%3Furi%20cdm%3Aofficial-journal-act_year%20%222024%22%5E%5Exsd%3AgYear.%0A%20%20%3Furi%20rdf%3Atype%20cdm%3Aofficial-journal-act.%0A%7D&format=text%2Fhtml&timeout=0&debug=on&run=+Run+Query+)

```sparql
prefix cdm: <http://publications.europa.eu/ontology/cdm#>
prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
prefix xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT ?uri
WHERE {
  ?uri cdm:official-journal-act_year "2024"^^xsd:gYear.
  ?uri rdf:type cdm:official-journal-act.
}
```

### [Training example: Official Journal act and business identifier](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryOfficialJournalActBusinessId)

Training-deck example that connects Official Journal acts to business identifiers using owl:sameAs.

Target endpoint: [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this)

Live query: [Run live query](http://publications.europa.eu/webapi/rdf/sparql?default-graph-uri=&query=prefix%20cdm%3A%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23%3E%0Aprefix%20owl%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2002%2F07%2Fowl%23%3E%0Aprefix%20xsd%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2001%2FXMLSchema%23%3E%0ASELECT%20DISTINCT%20%3Fc_act%20%3Fact%0AWHERE%20%7B%0A%20%20%3Fc_act%20owl%3AsameAs%20%3Fact.%0A%20%20%3Fc_act%20cdm%3Aofficial-journal-act_year%20%222024%22%5E%5Exsd%3AgYear.%0A%20%20FILTER(regex(str(%3Fact)%2C%20%22%2Foj%2F%22))%0A%7D&format=text%2Fhtml&timeout=0&debug=on&run=+Run+Query+)

```sparql
prefix cdm: <http://publications.europa.eu/ontology/cdm#>
prefix owl: <http://www.w3.org/2002/07/owl#>
prefix xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT DISTINCT ?c_act ?act
WHERE {
  ?c_act owl:sameAs ?act.
  ?c_act cdm:official-journal-act_year "2024"^^xsd:gYear.
  FILTER(regex(str(?act), "/oj/"))
}
```

### [Training example: retrieve case-law created in a date range](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryCaseLawDateRange)

Training-deck practical-session example for case-law classes, ECLI identifiers, titles, and creator agents.

Target endpoint: [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this)

Live query: [Run live query](http://publications.europa.eu/webapi/rdf/sparql?default-graph-uri=&query=prefix%20cdm%3A%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23%3E%0Aprefix%20xsd%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2001%2FXMLSchema%23%3E%0Aselect%20distinct%20%3Fw%20%3Fclass%20%3Fecli%20%3Ftitle%20%3Fagent%0Awhere%20%7B%0A%20%20%3Fw%20a%20%3Fclass.%0A%20%20%3Fw%20cdm%3Adate_creation_legacy%20%3Fdatedoc.%0A%20%20OPTIONAL%20%7B%20%3Fw%20cdm%3Acase-law_ecli%20%3Fecli.%20%7D%0A%20%20OPTIONAL%20%7B%0A%20%20%20%20%3Fe%20cdm%3Aexpression_belongs_to_work%20%3Fw.%0A%20%20%20%20%3Fe%20cdm%3Aexpression_uses_language%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fresource%2Fauthority%2Flanguage%2FENG%3E.%0A%20%20%20%20%3Fe%20cdm%3Aexpression_title%20%3Ftitle.%0A%20%20%20%20%3Fw%20cdm%3Awork_created_by_agent%20%3Fagent.%0A%20%20%7D%0A%20%20FILTER(%3Fdatedoc%20%3E%3D%20%222022-01-01%22%5E%5Exsd%3Adate%20%26%26%20%3Fdatedoc%20%3C%20%222022-12-01%22%5E%5Exsd%3Adate)%0A%20%20FILTER(%3Fclass%20in%20(%0A%20%20%20%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23document_cjeu%3E%2C%0A%20%20%20%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23court-report%3E%2C%0A%20%20%20%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23case-law%3E%2C%0A%20%20%20%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23summary_case-law%3E%2C%0A%20%20%20%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23summary_case-law_jure%3E%0A%20%20))%0A%7D%0Aorder%20by%20%3Fclass&format=text%2Fhtml&timeout=0&debug=on&run=+Run+Query+)

```sparql
prefix cdm: <http://publications.europa.eu/ontology/cdm#>
prefix xsd: <http://www.w3.org/2001/XMLSchema#>
select distinct ?w ?class ?ecli ?title ?agent
where {
  ?w a ?class.
  ?w cdm:date_creation_legacy ?datedoc.
  OPTIONAL { ?w cdm:case-law_ecli ?ecli. }
  OPTIONAL {
    ?e cdm:expression_belongs_to_work ?w.
    ?e cdm:expression_uses_language <http://publications.europa.eu/resource/authority/language/ENG>.
    ?e cdm:expression_title ?title.
    ?w cdm:work_created_by_agent ?agent.
  }
  FILTER(?datedoc >= "2022-01-01"^^xsd:date && ?datedoc < "2022-12-01"^^xsd:date)
  FILTER(?class in (
    <http://publications.europa.eu/ontology/cdm#document_cjeu>,
    <http://publications.europa.eu/ontology/cdm#court-report>,
    <http://publications.europa.eu/ontology/cdm#case-law>,
    <http://publications.europa.eu/ontology/cdm#summary_case-law>,
    <http://publications.europa.eu/ontology/cdm#summary_case-law_jure>
  ))
}
order by ?class
```

### [Training example: retrieve acts put in force in 2022 and still in force](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryActsInForce2022)

Training-deck practical-session example for legal acts in force, entry-into-force dates, and grouped document identifiers.

Target endpoint: [CELLAR Virtuoso SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fwebapi%2Frdf%2Fsparql%23this)

Live query: [Run live query](http://publications.europa.eu/webapi/rdf/sparql?default-graph-uri=&query=prefix%20cdm%3A%20%3Chttp%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23%3E%0Aprefix%20xsd%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2001%2FXMLSchema%23%3E%0Aselect%20%3Fact%20%3Fdate_entry_into_force%20(GROUP_CONCAT(%3FactID%3B%20separator%3D%22%2C%22)%20as%20%3FactIds)%0Awhere%20%7B%0A%20%20%3Fact%20cdm%3Aresource_legal_in-force%20%22true%22%5E%5Exsd%3Aboolean.%0A%20%20%3Fact%20cdm%3Aresource_legal_date_entry-into-force%20%3Fdate_entry_into_force.%0A%20%20%3Fact%20cdm%3Awork_id_document%20%3FactID.%0A%20%20FILTER(%3Fdate_entry_into_force%20%3E%3D%20%222022-01-01%22%5E%5Exsd%3Adate%20%26%26%20%3Fdate_entry_into_force%20%3C%20%222023-01-01%22%5E%5Exsd%3Adate)%0A%7D%0Agroup%20by%20%3Fact%20%3Fdate_entry_into_force%0Aorder%20by%20%3Fdate_entry_into_force&format=text%2Fhtml&timeout=0&debug=on&run=+Run+Query+)

```sparql
prefix cdm: <http://publications.europa.eu/ontology/cdm#>
prefix xsd: <http://www.w3.org/2001/XMLSchema#>
select ?act ?date_entry_into_force (GROUP_CONCAT(?actID; separator=",") as ?actIds)
where {
  ?act cdm:resource_legal_in-force "true"^^xsd:boolean.
  ?act cdm:resource_legal_date_entry-into-force ?date_entry_into_force.
  ?act cdm:work_id_document ?actID.
  FILTER(?date_entry_into_force >= "2022-01-01"^^xsd:date && ?date_entry_into_force < "2023-01-01"^^xsd:date)
}
group by ?act ?date_entry_into_force
order by ?date_entry_into_force
```

### [European Data Portal endpoint smoke test](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23queryDataEuropaCrossPortal)

A small cross-portal query for validating the European Data Portal SPARQL endpoint included in the mesh.

Target endpoint: [European Data Portal SPARQL Endpoint](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fdata.europa.eu%2Fdata%2Fsparql%23this)

Live query: [Run live query](https://data.europa.eu/data/sparql?query=select%20%3Fs%20%3Fp%20%3Fo%0Awhere%20%7B%0A%20%20%3Fs%20%3Fp%20%3Fo%20.%0A%7D%0Alimit%2010&format=text%2Fhtml)

```sparql
select ?s ?p ?o
where {
  ?s ?p ?o .
}
limit 10
```

## HowTo

1. [Frame the workload](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23howToStep1): Decide whether the task is metadata discovery, relationship traversal, identifier resolution, content retrieval, or notification monitoring.
2. [Account for harvested EU datasets](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23howToStep2): Identify which EU datasets, vocabularies, identifiers, and publication streams need to be harmonized into the operational knowledge graph.
3. [Validate Linked Data deployment](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23howToStep3): Check that domain entities use durable IRIs, resolver-friendly RDF descriptions, typed relationships, and cross-graph links that can be followed by humans and agents.
4. [Set performance and availability criteria](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23howToStep4): Treat 24/7 uptime, SPARQL latency, graph size, concurrency, and operational monitoring as mandatory acceptance criteria.
5. [Choose the interface](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23howToStep5): Use Virtuoso/SPARQL for discovery and relationship questions; use the REST API when the content or notice target is already known.
6. [Inspect the query pattern](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23howToStep6): Open the SPARQL accordion that matches the workload and review the query body, endpoint, and modeled RDF entity links.
7. [Adapt and run the query](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23howToStep7): Use the live query link as a starting point, replacing visible placeholders where the source template requires a value.
8. [Trace the RDF model](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23howToStep8): Use the KG Explorer and resolver-backed links to inspect how the use-case entities, endpoints, query templates, and source documents connect.

## FAQ

### [What is the Virtuoso use case?](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23faqWhatUseCase)

Cellar shows Virtuoso used as an RDF triple-store and SPARQL access platform for high-value EU publication metadata and semantic repository workloads.

### [Why is Virtuoso central to this model?](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23faqWhyVirtuoso)

The Cellar training material identifies the knowledge graph triple store as Virtuoso and explains that RDF triples are queried with SPARQL through the Virtuoso endpoint.

### [Why is 24/7 knowledge graph access important?](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23faqWhy24x7)

Cellar-like public knowledge graphs serve institutions, citizens, applications, and AI agents continuously, so durable availability is part of the use case rather than an optional deployment detail.

### [How is Cellar similar to DBpedia?](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23faqHowLikeDbpedia)

Both are public knowledge graph patterns where heterogeneous source data is transformed into RDF, published with Linked Data principles, and made available through Virtuoso-powered access paths.

### [Why are Linked Data principles essential?](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23faqWhyLinkedData)

Linked Data principles turn the graph into a Semantic Web surface: identifiers can be resolved, RDF descriptions can be followed, and agents can traverse typed relationships instead of scraping isolated pages.

### [Why are performance and scalability non-negotiable?](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23faqWhyPerformance)

A public EU knowledge graph must handle large data volumes, multilingual metadata, concurrent use, and unpredictable agent workloads while keeping SPARQL discovery responsive.

### [How do AI agents benefit from this architecture?](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23faqHowAgentsBenefit)

AI agents can ground answers and workflows in dereferenceable IRIs, SPARQL query results, controlled vocabularies, and reusable graph relationships rather than brittle text-only context.

### [What workloads does the use case demonstrate?](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23faqWhatWorkloads)

The use case demonstrates WEMI hierarchy traversal, Official Journal retrieval, EU Whoiswho lookups, identifier resolution, vocabulary queries, and assistant-mediated SPARQL templates.

### [Which SPARQL endpoint should be used for Cellar?](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23faqWhatEndpoint)

The Cellar SPARQL endpoint is http://publications.europa.eu/webapi/rdf/sparql, modeled here as a WebAPI and linked to sample query entities.

### [What is the REST/SPARQL boundary?](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23faqRestVsSparql)

REST is appropriate for retrieving known content streams and metadata notices; SPARQL is appropriate for list, discovery, relationship, and metadata query workloads.

### [Why does WEMI matter?](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23faqWhatIsWemi)

WEMI structures publications as Work, Expression, Manifestation, and Item, letting users retrieve language and format variants of a publication.

### [How does the Cello assistant fit?](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23faqHowCelloFits)

Cello is modeled as an AI-assisted application that maps user requests to SPARQL templates targeting the Cellar public knowledge graph.

### [Why include the European Data Portal endpoint?](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23faqDataEuropa)

It provides cross-portal linked data context and another EU SPARQL service endpoint in the mesh.

## Glossary

- [Cellar](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23cellarProject): The Publications Office common data repository and semantic repository.
- [Cellar Knowledge Graph](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23cellarKnowledgeGraph): Cellar metadata stored as RDF triples and queried with SPARQL.
- [Virtuoso](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fdbpedia.org%2Fresource%2FVirtuoso_Universal_Server): The triple store/SPARQL platform identified in the Cellar training material.
- [DBpedia](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fdbpedia.org%2Fresource%2FDBpedia): A public 24/7 knowledge graph powered by Virtuoso and used here as a reference pattern.
- [Linked Data principles](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fdbpedia.org%2Fresource%2FLinked_data): HTTP IRI, RDF description, and interlinking rules that let graph resources resolve and connect across the Web.
- [Semantic Web](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fdbpedia.org%2Fresource%2FSemantic_Web): A Web of machine-readable, typed, linked resources that humans, applications, and AI agents can traverse.
- [24/7 knowledge graph](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23twentyFourSevenAvailability): Continuously available graph service for human and machine access.
- [AI agent access](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23humanAndAgentAccess): Machine access pattern where agents use IRIs, RDF, SPARQL, and vocabularies as operational context.
- [Scalability](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23highPerformanceScalability): Capacity to sustain large graphs, concurrent access, and responsive query workloads.
- [CDM](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23this): Common Data Model ontology used for Cellar metadata.
- [WEMI](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fdbpedia.org%2Fresource%2FFunctional_Requirements_for_Bibliographic_Records): Work, Expression, Manifestation, Item model for publication variants.
- [Cellar identifiers](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fresource%2Fcellar%2F%23this): Canonical Cellar resource identifiers used as normalized graph subjects.
- [Official Journal Act](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23official-journal-act): CDM resource type used for post-2024 Official Journal act examples.
- [Case-law](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fontology%2Fcdm%23case-law): CDM class family for CJEU and related case-law resources.
- [Date-range filtering](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fop.europa.eu%2Fen%2Fweb%2Fcellar%2F%23dateRangeFiltering): SPARQL pattern using typed date comparisons for temporal workloads.
- [METS](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fwww.loc.gov%2Fstandards%2Fmets%2F%23this): Packaging standard used during Cellar ingestion.
- [CELEX](https://linkeddata.uriburner.com/describe/?url=http%3A%2F%2Fpublications.europa.eu%2Fresource%2Fcelex%2F%23this): Identifier scheme for EU legal publications.
- [Cello](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fgithub.com%2FOpenLinkSoftware%2FAssistants%2Fblob%2Fmain%2Fcello-config.md%23this): Assistant configuration for querying Cellar with SPARQL templates.

## Attribution

Generated with [gpt5-chat](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fopenai.com%2F%23gpt5-chat) in [Codex desktop](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fopenai.com%2Fcodex%2F%23desktop) using [document-to-kg-skill](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fgithub.com%2FOpenLinkSoftware%2Fai-agent-skills%2Ftree%2Fmain%2Fdocument-to-kg-skill), [kg-generator](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fgithub.com%2FOpenLinkSoftware%2Fai-agent-skills%2Ftree%2Fmain%2Fkg-generator), and [rdf-infographic-skill](https://linkeddata.uriburner.com/describe/?url=https%3A%2F%2Fgithub.com%2FOpenLinkSoftware%2Fai-agent-skills%2Ftree%2Fmain%2Frdf-infographic-skill).

Resolver pattern: visible semantic entities use [URIBurner describe links](https://linkeddata.uriburner.com/fct) via `https://linkeddata.uriburner.com/describe/?url={uri}`.