Reference Data
Code lists, hierarchies and currencies — small, shared, and quietly load-bearing.
5 to work through
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beginner
An order total is stored as the integer 1000 alongside a currency code. In USD that is ten dollars. The same integer means one thousand yen in JPY and one dinar in KWD. A report sums the column across currencies and the total looks plausible. Why is this a reference-data problem rather than a bug in the report?
3 min answer -
intermediate
A reference data set of branch codes is maintained by an operations team. A branch closes in March and its code is retired. In September the code is assigned to a new branch in another city. Six months later finance asks why one branch's historical performance looks impossible. What happens across the estate?
2 min answer -
intermediate
Tax rates change annually and must apply from a specific date. How do you manage that across a dozen systems?
2 min answer -
advanced
A travel platform's currency, tax and geography reference data changes over time. Bookings must be reproducible years later. What does the reference data architecture need?
1 min answer -
advanced
Twilio's public Messages API documents a fixed set of message status values, and the initial value depends on how the message was created - accepted when a Messaging Service is used, queued when it is not. Every customer who writes an exhaustive match over that list inherits a dependency on it. What does publishing a code list as part of an API force on its owner, and where would copying that approach be a mistake?
3 min answer
3 terms in this topic
Code List Governance
Managing the small shared enumerations — currencies, country codes, statuses, product categories — whose uncontrolled change breaks systems quietly.
conceptIdentifier Reuse Hazard
The silent corruption that occurs when a retired code or key is later assigned to a different real-world entity, so historical facts join to the wron…
conceptReference Data
The slowly-changing shared vocabularies — country codes, currencies, product categories, tax rates — whose inconsistency causes disproportionate trouble.
Neighbouring topics
Data Governance & Semantics
General material on ownership, meaning, quality and control of data at enterprise scale.
Data Mesh
Domain ownership, data as a product, self-serve platform, and federated governance.
Data Products
A dataset with an owner, an interface, an SLO, and consumers who can rely on it.
Data Contracts
Producers committing to schema, semantics and freshness, and breaking builds when they do not.
Data Catalog
Discovery, ownership and technical metadata, and why catalogues go stale.
Business Glossary
Agreeing what a term means before arguing about which number is right.
Semantic Layer
Metric definitions held once and served to every tool that asks.
Master Data Management
One authoritative record for a customer or product across systems that each have their own.
Data Quality Dimensions
Completeness, accuracy, timeliness, consistency, validity and uniqueness as testable claims.
Data Observability
Freshness, volume, schema and distribution monitoring for pipelines that fail silently.
Data Stewardship
The operating model that makes ownership a role rather than a slide.
Data Access Models
Role, attribute and purpose-based access over analytical data, and how they compose.
Row & Column-Level Security
Restricting slices of a table rather than the whole table, and where it is enforced.
Tokenisation & Masking
Dynamic masking, deterministic tokens, and preserving joinability without exposure.
Retention & Purge
Deleting from an append-only estate, and proving the deletion happened.
Data Sharing & Clean Rooms
Collaborating on data neither party may hand over, with computation as the interface.
Sensitivity Labelling
Propagating a classification through joins and derived tables so controls follow the data.
BI Governance
Dashboard sprawl, certified reports, and the number the board is allowed to see.
Self-Service vs Governed
Letting analysts move fast without four teams reporting four different revenues.