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Data Modeling Made Simple with CA ERwin Data Modeler r8 by Steve Hoberman, Donna Burbank

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Recall the summary of all three normalization levels: Every data element must provide a fact about the key, the whole key, and nothing but the key. First Normal Form (1NF) is the Every data element must provide a fact about the key part. Second Normal Form (2NF) is “the whole key” part. This means each entity must have the minimal set of data elements that uniquely identifies each entity instance.

For example, in Figure 18.12, we have Employee Assignment.

Figure 18.12 Example of Model not in 2NF

The primary key of Employee Assignment is Employee Identifier and Department Identifier. Do we have the minimal primary key ...

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