Three-tier approach to model design
When designing a model in IBM Cognos Framework Manager, the recommended approach is to use a tiered design. The most common is a three-tier design. In a three-tier design, you will include a database layer, a business layer, and a presentation layer. There is some debate within the Cognos community as to whether or not the third tier is really necessary or if it is better to combine the business layer and presentation layer into one to make it a total of a two-tier model. While this can be done and works great in most scenarios, there are reasons for creating the habit of using a three-tier approach.
One major reason for using the database view layer is that it allows you to import your table structures exactly as they exist in the underlying database. By not changing anything here, you protect yourself against potential issues in case the underlying database tables change. In the database layer, some purists will not even import relationships because of...
