Modeling query subjects that represent descriptive data

IBM® Cognos® dimensional modeling requires that you apply star schema principles to the logical layers of the model.

Normalized or snowflaked data sources often have several tables that describe a single business concept. For example, a normalized representation of Product may include four tables related by 1..n relationships. Each Product Line has one or more Product Types. Each Product Type has one or more Products. Products have names and descriptions in multiple languages so they exist in the Product Multilingual lookup table.

the normalized view of product which includes four tables - product line, product type, product and product multilingual

One way to simplify the model is to create one model query subject for each descriptive business concept. Your users may not know the relationship between the individual query subjects so it is helpful to group them together; in addition, having to expand each model object and select a query item requires more effort.

The next step for analysis is to create a regular dimension with a level for each query subject.