Data engineering·Governance, privacy and meaning
a free-text notes column turned out to contain names and phone numbers, and it had been copied into six downstream tables.
Personally identifiable information
Also calledPII, personal data
Data that identifies a person directly or in combination with other fields. What makes it hard in a warehouse is not the obvious columns but the propagation: it arrives in unstructured fields, gets joined, copied into marts and exported, and a control applied only at the source protects none of the copies. Classification therefore has to travel with lineage or it is decorative.