Data engineering·Modelling for analysis
a customer moved from Leeds to Bristol, and now you have to decide whether their orders from last year happened in Leeds or in Bristol.
Slowly changing dimension
Also calledSCD, dimension history
The general problem of what to do when a descriptive attribute changes, given that facts referring to it have already been recorded. The numbered types are the standard answers, and choosing between them is a question for whoever reads the report rather than for the modeller. It is the classic warehouse conversation because both answers are defensible and only one of them is what the finance team assumed.