Matt Allington

“You should have one lookup table for each “object” that you need for reporting purposes. For example, in the data being used here, these objects are customers, products, territories, and time (i.e., calendar). A key feature of a lookup table is that it contains one and only one row for each individual item in the table, and it has as many columns as needed to describe the object.”
― Matt Allington, Supercharge Power BI: Power BI Is Better When You Learn to Write DAX