Key Dimensions of a Database
The first step in determining the key dimensions of a database is to identify the main dimensions for each candidate fact table. This can be achieved by looking at the logical model, and finding out which entities are associated with the entity representing the fact table. The challenge here is to focus on the key dimension entities, which may not be the ones directly associated to the fact entity. For example, in a retail banking data warehouse, we may have identified account transactions as a candidate fact table, but the relationship between account transaction and customer may be indirect, such as through the account entity, and the account relationship.