Which normal forms require that non-key columns be functionally dependent solely on the primary key?
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Second
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Fifth
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Third
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None of above
Third Normal Form (3NF) requires that all non-key attributes are functionally dependent only on the primary key, eliminating transitive dependencies where a non-key attribute depends on another non-key attribute. 2NF only addresses partial dependencies, while 5NF deals with join dependencies.
Third Normal Form (3NF) requires that every non-key column depend on 'the key, the whole key, and nothing but the key' — meaning non-key attributes must be functionally dependent solely on the primary key, with no transitive dependency through another non-key column. Second Normal Form only addresses partial dependencies on a composite key (not full 'solely on the key' independence from other non-key columns), and Fifth Normal Form deals with join dependencies, a different concern entirely. So Third is the form this description matches.