Physical Database Design

120 CHAPTER 6 Shared-nothing Partitioning

false sharing,

7

because each data node will use its CPUs independently of the

others.

6.9 Where the Money Goes

Shared-nothing partitioning remains most useful for complex query processing, which

is a hallmark of data warehousing and decision support systems. These systems are usu-

ally expensive. After reading this chapter you may think the reason for the expense is the

cost of all the components. In fact the dominant expense in most warehousing systems

is storage, which is always the most expensive component in a warehouse. In fact the

cost of storage is itself very cheap. In Fall 2006 multiple companies began selling ter-

abyte-sized drives for only $500 U.S. However, these high-volume inexpensive drives