Building a single source of truth

Once you have the concept of a star schema, it is time to move on to conformed dimensions. Additional star schemas can be linked together through a common dimension with the same surrogate keys. Using this extension to a star schema will assist the Analysis Services engine to use measures between fact tables to relate based on a dimension attribute. This process is known as a hub and spokes data warehouse. Figure 10.5 displays conformed dimensions – Date, SalesTerritory, and Product – related to two different fact tables – ResellerSales and InternetSales.

Figure 10.5 – Conformed dimensions

So, instead of creating two different semantic models, InternetSales versus ResellerSales, we can consolidate those into one semantic model called Sales. Conformed dimensions make this a single source of truth because the measure calculations for ResellerSales and InternetSales can be contained in one model...