Data Modeling Question: Download Questions PDF
What is an artificial (derived) primary key? When should it be used?
Using a name as the primary key violates the principle of stability. The social security number might be a valid choice, but a foreign employee might not have a social security number. This is a case where a derived, rather than a natural, primary key is appropriate. A derived key is an artificial key that you create. A natural key is one that is already part of the database.
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|Is this statement TRUE or FALSE? all databases must be in third normal form?
|What is second normal form?