Book Image

Expert Cube Development with SSAS Multidimensional Models

By : Alberto Ferrari, Marco Russon, Chris Webb
Book Image

Expert Cube Development with SSAS Multidimensional Models

By: Alberto Ferrari, Marco Russon, Chris Webb

Overview of this book

Table of Contents (19 chapters)
Expert Cube Development with SSAS Multidimensional Models
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Many-to-many dimension relationships


In the dimensional model, the fact table has a many-to-one relationship with each dimension. However, sometimes this kind of modeling cannot represent the real world: for example, a product might belong to several categories. One way of solving this problem might be to choose a "primary" category for each product, to allow the use of a classical star schema. But, doing this, we lose possibly important information.

Analysis Services 2005 introduced the ability to handle many-to-many relationships between dimensions. This feature brings to the OLAP world the approach of modeling many-to-many relationships using bridge tables or factless fact tables that we saw in Chapter 2, Building Basic Dimensions and Cubes.

Implementing a many-to-many dimension relationship

Our example scenario for implementing a many-to-many relationship is based on Sales Reason. In Adventure Works, each Internet sale has a list of reasons for the transaction. This list is the result of...