REQUIREMENTS OF THE CONCEPTUAL MODEL
Before proceeding, the general requirements of a conceptual data model for data warehousing are restated succinctly. The model must provide for the following:
Be simple to understand and use by nontechnical people
Support the GCM
The most widely used data models are entity relationship (ER) or sometimes, extended entity relationship (EER) methods. These models are widely understood by IT professionals but are not easy for non-IT people to understand. A properly produced ER model contains quite a lot of syntax when you think about it. We have rules regarding cardinality, participation conditions, inclusive and exclusive relationships, n-ary relationships, and entity supertypes and subtypes. These ...