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Exercise No. 44: Tri-County Hospital (log)

This cube stores data about patients treated in the Tri-County Hospital.

We have four dimensions with the following hierarchical structure (the dimension "patient" features a parallel hierarchy at level 1):

Table L.E.58.1 - Tri-County Hospital

There is only one key figure in this example, costs (of the treatment). All additional attributes have been grafted.

Please draw the Classic Star and the Fact Constellation Schema. Then draw the dimension tables normalized!

Solution

This case's Classic Star Schema has five tables, a central fact table and four dimension tables. The latter consist of a generated key as well as a key and a text field for each hierarchy (except the total aggregation) and the level attribute. The fact table uses the generated keys from the dimension tables as a combined key and contains one key figure ("costs") in this example:

Figure L.E.58.1 - The Classic Star Schema

The Fact Constellation Schema for this case consists of four dimension tables and 30 fact tables (1x2x3x5):

Figure L.E.58.2 - The Fact Constellation Schema

Normalizing the dimension tables completely means that only the key of the next higher level is kept in each table. Please note that the tables for the total aggregation level have been neglected in Figure L.E.58.3.

Figure L.E.58.3 - DT normalized

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