The resulting view then appears to have a simple Diagnosis key that joins to our Diagnosis table in the healthcare example. The view can also predefine the multiplication of the weighting factor with any additive facts in the fact table. I have seen two other situations besides healthcare where a multivalued dimension makes sense. In addition to the Diagnosis example discussed in this column, I have built multivalued dimensions for retail banks and standard industry classifications. If the bank wants to associate individual customers with account balances, then the Account dimension must play the same role as the Diagnosis Group dimension in the healthcare example.
Banks are quite interested in both correctly weighted reports and impact reports.
Standard Industry Classifications. This term defines the so-called SIC code that is assigned to a commercial enterprise to describe what industry segment they are in. The problem with SIC codes is that all big enterprises are represented by multiple SIC codes. If you encode a fact table with an SIC dimension, you have the same problem as with the multiple diagnoses. SIC codes are really quite useful, however.