The greatest strength of PowerPivot is it’s ability to create relationship with different sources of data and piggyback on this relationship for various kinds of analysis. PowerPivot relationship requires one-to-many relationship between the parent and child tables. But what happens if the relationship between parent and child tables is many-to-many instead? For e.g. you might want to establish a relationship between a fact table that has a Business Key to the dimension table and that dimension table maintains history. In this post I explain how to establish a relationship between two tables that do not exhibit one-to-many relationship on their Business Key using a technique that is similar to an ETL Type 2 SCD lookup using Data Analysis Expressions (DAX).
Continue Reading