Rdf Post

Capabilities

IRI-to-URN Mapping

RDF IRIs are converted to DataHub URNs following this pattern:

http://example.com/finance/credit-risk
→ urn:li:glossaryTerm:example.com/finance/credit-risk

IRI path segments create the glossary node hierarchy:

• example.com → Glossary Node
• finance → Glossary Node (child of example.com)
• credit-risk → Glossary Term (under finance node)

Supported RDF Vocabularies

The source recognizes entities from these standard vocabularies:

• SKOS: skos:Concept → Glossary Term, skos:prefLabel → name, skos:definition → definition, skos:broader/skos:narrower → relationships
• OWL: owl:Class → Glossary Term, owl:NamedIndividual → Glossary Term
• RDFS: rdfs:label → name (fallback), rdfs:comment → definition (fallback)

Limitations

• MVP Scope: The current implementation focuses on glossary terms and relationships. Dataset, lineage, and structured property extraction are not included.
• Relationship Types: Only skos:broader and skos:narrower relationships are extracted. skos:related and skos:exactMatch are not supported.
• Term Requirements: Terms must have a label (skos:prefLabel or rdfs:label) of at least 3 characters to be extracted.
• Large Files: Very large RDF files are loaded entirely into memory. Consider splitting large ontologies into multiple files.

Troubleshooting

No glossary terms extracted

• Check term types - Ensure entities are typed as skos:Concept, owl:Class, or owl:NamedIndividual
• Verify labels - Terms must have skos:prefLabel or rdfs:label with at least 3 characters
• Check file format - Verify the RDF file is valid and in a supported format
• Review logs - Enable debug logging: datahub ingest -c recipe.yml --debug

Terms not appearing in correct hierarchy

• Check IRI structure - Glossary nodes are created from IRI path segments
• Verify IRI format - IRIs should be absolute (e.g., https://example.com/path/term)

Relationships not extracted

• Check relationship types - Only skos:broader and skos:narrower are supported
• Verify term existence - Both source and target terms must exist in the RDF
• Check export options - Ensure relationship is not in skip_export

Stateful ingestion not working

• Enable it - Set stateful_ingestion.enabled: true
• Check server - Verify your DataHub server supports stateful ingestion (version >= 0.8.20)