The Semantic Medallion

RDF, ontology, representative data, and executable SPARQL for a Gold-layer knowledge graph-powered data catalog.

RDF TurtleJSON-LDMarkdown

Overview

The article reframes Bronze-Silver-Gold as semantic enrichment: Bronze lands raw data, Silver adds stable IRIs, and Gold publishes harmonized RDF. This artifact set turns that pattern into an executable graph.

Semantic Medallion

A medallion architecture variant where the Gold layer is an RDF knowledge graph.

IRI minting

The practice of assigning stable, globally unique identifiers to entities during the Silver layer.

Gold Graph

Harmonized RDF graph mapped to a shared ontology and published for SPARQL queries.

Customer

A harmonized customer entity identified by a stable IRI.

Contract

A contractual relationship or agreement involving a customer.

Executable SPARQL examples

Each query is modeled in RDF as schema:SoftwareSourceCode, targets URIBurner SPARQL, and uses the DAV named graph IRI for the generated Turtle graph.

Find customers with billing issues and active contracts

Source image query selected customers with active contracts and balances greater than zero.

Run live query Endpoint

PREFIX sm: <https://moderndata101.substack.com/p/the-semantic-medallion#>
SELECT ?customer ?name ?balance ?contractStatus
WHERE {
  GRAPH <https://linkeddata.uriburner.com/DAV/demos/daas/semantic-medallion-gpt5-chat-1.ttl> {
    ?customer a sm:Customer ;
      sm:name ?name ;
      sm:hasBillingAccount ?account ;
      sm:hasContract ?contract .
    ?account sm:outstandingBalance ?balance .
    ?contract sm:status ?contractStatus .
    FILTER(?contractStatus = "Active" && ?balance > 0)
  }
}
Find datasets that contain customer information

Source image query used DCAT distribution metadata and customer instances to discover datasets.

Run live query Endpoint

PREFIX sm: <https://moderndata101.substack.com/p/the-semantic-medallion#>
PREFIX dcat: <http://www.w3.org/ns/dcat#>
PREFIX dct: <http://purl.org/dc/terms/>
SELECT ?dataset ?title
WHERE {
  GRAPH <https://linkeddata.uriburner.com/DAV/demos/daas/semantic-medallion-gpt5-chat-1.ttl> {
    ?dataset a dcat:Dataset ;
      dct:title ?title ;
      dcat:distribution ?dist .
    ?dist dcat:accessURL ?endpoint .
    ?customer a sm:Customer .
  }
}
Show every property and value about customer C-001

Source image query used <https://example.org/customer/C-001> ?property ?value.

Run live query Endpoint

PREFIX sm: <https://moderndata101.substack.com/p/the-semantic-medallion#>
SELECT ?property ?value
WHERE {
  GRAPH <https://linkeddata.uriburner.com/DAV/demos/daas/semantic-medallion-gpt5-chat-1.ttl> {
    sm:customer-C-001 ?property ?value .
  }
}
Which sources contribute to customer records?

Source image query grouped :Customer records by :sourceSystem.

Run live query Endpoint

PREFIX sm: <https://moderndata101.substack.com/p/the-semantic-medallion#>
SELECT ?source (COUNT(?customer) AS ?records)
WHERE {
  GRAPH <https://linkeddata.uriburner.com/DAV/demos/daas/semantic-medallion-gpt5-chat-1.ttl> {
    ?customer a sm:Customer ;
      sm:sourceSystem ?source .
  }
}
GROUP BY ?source

Knowledge Graph Explorer

RDF Graph Workbench

Explore the generated ontology, representative instances, query examples, DCAT metadata, and provenance graph derived from the companion RDF.

0 nodes / 0 links

Graph data embedded from companion RDF at generation time. Click the graph to arm zoom; click outside the explorer to release page scrolling.