Building the Data Warehouse

Chapter 13. The Relational and the Multidimensional Model as a Basis for Database Design

One of the issues facing data warehousing professionals is that of the basic model for data warehouse database design. There are two basic models for database design that are widely considered — the relational model and the multidimensional model. The relational model is widely considered to be the "Inmon" approach, while the multidimensional model is considered to be the "Kimball" approach to design for the data warehouse.

This chapter addresses what the different approaches are and how they apply to data warehousing. Both approaches have their advantages and disadvantages. Those advantages and disadvantages are discussed, and the conclusion is drawn that the relational foundation for database design is the best long-term approach for the building of the data warehouse and for the case where a true enterprise approach is needed. The multidimensional model is good for short-term data warehouses, where there is a limited scope for the data warehouse.

The Relational Model

The relational approach to database design begins with the organization of data into a table. Different columns are in each row of the table. Figure 13-1 shows a simple table.

Note

For the definitive work on the relational model and relational database design, refer to the books and articles by Ted Codd and Chris Date.

The relational table can have different properties. The columns of data have different physical characteristics. Different ...