The product and customer dimension views retrieve both the surrogate key column used for relationships in the dataset as well as the business key that uniquely identifies the given product or customer, respectively. For example, the same product (FR-M94B-38) is represented by three product dimension rows (304, 305, 306) due to changes in its list price over time:
As discussed in Chapter 1, Planning Power BI Projects, the historical tracking of core business entities, such as customers and products, via slowly-changing dimension ETL processes is an essential requirement for data warehouses. The ability to insert and update rows based off of changes in specific columns is well outside the scope of SQL views and M query transformations.