Create Silver DataFrames and mint stable IRIs for entities.
Structure and identify records
Gold changes from clean joined tables into harmonized RDF mapped to a shared ontology.
Answer 3
Dataset, distribution, and provenance metadata modeled with DCAT and PROV-O.
DCAT catalog layer
Representative customer instance used by the executable SPARQL examples.
Carla Nguyen
Knowledge graph specialist, semantic technologies expert, author, and speaker cited as the contributing expert for the article.
Veronika Heimsbakk
Land raw data in the Bronze layer from APIs, databases, files, and registries.
Harvest source data
Harmonized RDF graph mapped to a shared ontology and published for SPARQL queries.
Gold Graph
Model datasets, distributions, services, and provenance as catalog metadata.
Describe datasets with DCAT
PROV-O links generated datasets to source datasets and harmonization activities.
Answer 6
Indicates that a data source contributes a record to the catalog.
contributesRecord
The article reframes the Gold medallion layer as a semantic knowledge graph built from Silver DataFrames with stable IRIs, ontology mappings, RDF, DCAT, and SPARQL.
Expert's Desk
An article explaining how a medallion architecture can publish its Gold layer as an RDF knowledge graph-backed data catalog.
The Semantic Medallion: Building a Knowledge Graph-Powered Data Catalog
An external registry that contributes entity identity or enrichment data.
ExternalRegistry
A source system or dataset feeding the medallion architecture.
DataSource
Local email property used in executable examples.
email
Connects a customer to a billing account.
hasBillingAccount
URL-encoded live query action for URIBurner SPARQL.
Run live query
Structured DataFrames with stable entity IRIs and source identifiers.
Silver
Representative external registry record.
Registry Company 67890
Use a shared vocabulary and OTTR-style templates to map columns to RDF properties.
Define ontology templates
DCAT standardizes catalog, dataset, distribution, and service metadata in RDF.
Answer 5
Representative billing account instance.
Billing B 001
Billing platform
Billing
Local coding environment used for artifact generation and validation.
Codex desktop
SPARQL queries both the business data and the catalog metadata in the same graph model.
Answer 8
Bob Smith
Bronze, Silver, and Gold layers reinterpreted as semantic enrichment layers.
Architecture
A Bronze, Silver, or Gold layer in a medallion architecture.
MedallionLayer
Generate the RDF graph and load it into a SPARQL-capable catalog endpoint.
Publish Gold RDF
Use SPARQL to inspect customer entities, sources, datasets, and lineage.
Query across data and metadata
What is entity resolution in this architecture?
SPARQL examples from the article adapted to the generated ontology and instance data.
Executable SPARQL examples
Connects a customer to a contract.
hasContract
Records the unpaid balance on a billing account.
outstandingBalance
The W3C Data Catalog Vocabulary used to describe catalogs, datasets, distributions, and data services.
DCAT
Representative contract instance.
Contract K 2024 002
Publisher of the article and curator of Modern Data topics.
Modern Data 101
What role does DCAT play?
A person or role responsible for compliance work.
ComplianceOfficer
DCAT catalog describing the generated customer knowledge graph.
Semantic Medallion catalog
Records a billing account payment method.
paymentMethod
Why is SPARQL important here?
A lightweight ontology and representative data model for the Semantic Medallion article's DataFrame-to-RDF catalog pattern.
Semantic Medallion executable catalog ontology
It maps structured DataFrames through templates into RDF triples.
Answer 7
Why mint IRIs in the Silver layer?
Language model environment used to generate this artifact set.
GPT-5 Chat
Questions and answers generated from the article.
Semantic Medallion FAQ
Connects an entity to an external registry record.
registeredIn
Defined terms used by the article and generated ontology.
Semantic Medallion glossary
Executable SPARQL query adapted from article example
Source image query used <https://example.org/customer/C-001> ?property ?value.
Show every property and value about customer C-001
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 . } }
Connects a downstream catalog object to an upstream dependency.
dependsOn
What is the key implementation risk?
Python mapping library used in the article to transform DataFrames into RDF.
maplib
The W3C provenance ontology used to trace derivation and generation activities.
PROV-O
Why does this help data catalogs?
Distribution for Customer parquet distribution.
Customer parquet distribution
It is a medallion architecture pattern where the Gold layer is published as a connected RDF knowledge graph.
Answer 1
Entity resolution, semantic search, and impact analysis capabilities gained from graph-backed catalog data.
Catalog capabilities
Local name property used in executable examples.
name
Source image query grouped :Customer records by :sourceSystem.
Which sources contribute to customer records?
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
The RDF publication layer that replaces isolated Gold tables with connected knowledge.
Default live endpoint for the generated executable query links.
URIBurner SPARQL endpoint
Representative activity that maps Silver customer DataFrames to Gold RDF.
Customer harmonization
What is the Semantic Medallion?
The catalog can answer semantic relationship questions directly instead of only listing tables and columns.
Answer 4
Unified customer records from CRM, billing, and registry
Customer Master Data
Unified customer records from CRM, billing, and registry.
Records the source-local identifier captured in the Silver layer.
sourceId
A regulatory filing that is compliance-related.
RegulatoryFiling
A semantic catalog capability enabled by the knowledge graph.
CatalogCapability
External company registry
External Registry
Generated the RDF knowledge graph and compliance model.
kg-generator skill
Contract K 2024 003
Connects an entity to its originating source system.
sourceSystem
Reusable template definitions for mapping tabular rows into RDF triples.
OTTR templates
Billing B 002
Registry Company 12345
Multiple source records can be linked to one entity using stable IRIs and equivalence relationships.
Answer 9
Source image query used DCAT distribution metadata and customer instances to discover datasets.
Find datasets that contain customer information
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 . } }
Stable IRIs give records durable identifiers that can connect data across source systems.
Answer 2
An audit record that is compliance-related.
AuditRecord
A medallion architecture variant where the Gold layer is an RDF knowledge graph.
Semantic Medallion
Raw harvested data from APIs, databases, file shares, and registries.
Bronze
A superclass for compliance-related catalog entities.
ComplianceRelated
The practice of assigning stable, globally unique identifiers to entities during the Silver layer.
IRI minting
Registry Company 34567
Source image query selected customers with active contracts and balances greater than zero.
Find customers with billing issues and active contracts
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) } }
The article emphasizes that stable identifier design should begin early.
Answer 10
Customer relationship management system
CRM
A catalog that describes data semantically and exposes relationships directly in RDF.
Knowledge graph-powered data catalog
Billing B 003
How is provenance represented?
A contractual relationship or agreement involving a customer.
Contract
Stores the query or traversal pattern used to answer a catalog question.
answerPattern
A data transformation activity that maps structured data into RDF.
HarmonizationActivity
Generated RDF-backed HTML and Markdown companion artifacts.
rdf-infographic-skill
Practical workflow implied by the article.
Build a Semantic Medallion catalog
What does maplib do?
What changes in the Gold layer?
Stores a question that the graph-powered catalog can answer.
catalogQuestion
A harmonized customer entity identified by a stable IRI.
Customer
Contract K 2024 001
Distribution for Customer graph SPARQL distribution.
Customer graph SPARQL distribution
Summary of the shift from clean Gold tables to connected Gold RDF.
Semantic medallion overview
Records a contract or operational status.
status
Alice Johnson
Linked Data resolver used for entity description links.
URIBurner
RDF database and SPARQL endpoint platform backing URIBurner.
OpenLink Virtuoso
A billing account associated with a customer.
BillingAccount