Data engineering·Quality, tests and knowing it is wrong
eight thousand fact rows point at a customer id that does not exist in the customer dimension.
Referential integrity check
Also calledrelationship test, orphan check, foreign key test
Checking that every foreign key has a matching row, in a system where the database does not enforce it. Analytical stores generally do not enforce constraints at all, so this is a test rather than a guarantee, and orphans are normal in a warehouse fed by several pipelines at different speeds. The interesting output is the trend: a stable orphan rate is a known timing artefact, a rising one is a broken load.