In the field of data warehousing, we often hear some personal or organizational debate about the theory of data warehousing, whether it belongs to Bill Inmon or Ralph Kimball faction. Below we will describe the difference between the two.
Bill Inmon Paradigm:
The Data Warehouse is part of a holistic business intelligence system. An enterprise has only one data warehouse, the Data mart information source originates from the Data warehouse. In the Data Warehouse, the information store conforms to the third paradigm.
Ralph Kimball Paradigm:
A data warehouse is a collection of all data marts within an enterprise, and information is always stored in multidimensional models.
There is no right or wrong in either of these ways, they represent two different philosophies of data warehousing. In reality, most enterprise Data Warehouse systems are closer to the Ralph Kimball approach. This is because most data warehouses are the work of one of the organizations at the outset, so they originate from the Data mart. It is only when many data marts are built that they evolve into a data warehouse.