Building a dimensional data model

About this task

To build a dimensional data model, you need a methodology that outlines the decisions you need to make to complete the database design. This methodology uses a top-down approach because it first identifies the major processes in your organization where data is collected. An important task of the database designer is to start with the existing sources of data that your organization uses. After the processes are identified, one or more fact tables are built from each business process. The following steps describe the methodology you use to build the data model.

A dimensional database can be based on multiple business processes and can contain many fact tables. However, to focus on the concepts, the data model that this section describes is based on a single business process and has one fact table.

To build a dimensional database:

Procedure

  1. Choose the business processes that you want to use to analyze the subject area to be modeled.
  2. Determine the granularity of the fact tables.
  3. Identify dimensions and hierarchies for each fact table.
  4. Identify measures for the fact tables.
  5. Determine the attributes for each dimension table.
  6. Get users to verify the data model.