Martin Schoombee explains the concept of role-playing dimensions and then explains how that works in the Power Bi world:
In technical terms a role-playing dimension is when a dimension table has multiple (foreign key) relationships to the same fact table. In more non-technical terms, it is when you have the same attribute (“Date” for instance) that can relate to the same metrics in different ways.
If you look at the data model below as an example, you can see the Date entity could be used to reference either the Invoice Date or Delivery Date from the Sales entity, changing the perspective of the metrics we’re looking at.
It’s a little surprising to me that there isn’t an easier way to handle this concept. Role-playing dimensions are a core part of the Kimball model, and they’re common enough that you’d expect support to be a bit simpler.Comments closed