Data Warehousing For Dummies®, 2nd Edition

Chapter 5. Relational Databases and Data Warehousing

In This Chapter

• Using relational databases, past and present

• Making relational databases work well for data warehousing

• Checking out relational database products for your data warehousing project

You don't, strictly speaking, have to store the contents of a data warehouse in a relational database. However, in nearly all situations, your project benefits significantly from the use of a relational database management system (RDBMS).

This chapter explains the use of relational database technology (today's overwhelmingly dominant database technology) for your data warehouse, including its benefits and challenges. Chapter 6 discusses alternative technologies that you can use to store and manage your data warehouse.

The 1990s generation of data warehousing implementations grew up on multidimensional databases, but the current marketplace is experiencing a clear-cut trend toward using relational databases, particularly for large-volume data warehouses (more than about 250 gigabytes of data). Multidimensional databases aren't dead — they can still provide value to smaller-scale environments (data warehouse lite systems or data marts, as discussed in Chapters 3 and 4, respectively).

The Old Way of Thinking

Jump back to 1995. The data warehousing revolution was picking up steam, and companies all over the U.S. (yours was probably one of them) and around the world were captivated by not only the concept of data warehousing, but also the principles ...