Slowly Changing Dimensions

Concepts: paScdPipeline

What They Want to Hear 'SCD Type 2 keeps a full history of changes. When a value changes, I close the current row by setting an end date, and insert a new row with the updated value and a new start date. This means I can always answer: what was the customer's address when they placed that order last March?' That is the answer. SCD is about preserving history so you can join facts to the dimension values that were true at the time.