92 Solving Operational Business Intelligence with InfoSphere Warehouse Advanced Edition
Nearly all dimensional models have one or more date and time dimensions.
These types of dimensions must be handled differently from other dimensions
such as geography or products. This is due to the additonal attributes that can
be applied to date and time dimensions.
If a dimension table includes a code then, where possible, include the code
description as well. For example, if a product is identified by a product code,
and each code represents a product name, include both the code and the
product name in the dimension table.
Normally, avoid having dimensional models include more than 10-15
dimension tables. If your model has more, look for dimension ...