Recognises a non-superkey determinant in a 3NF entity
An attribute or set of attributes determines another but is not a candidate key. Usually hides behind overlapping composite keys, so the entity is in 3NF and still has update anomalies.
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What it looks like in practice
Expected result: The determinant, what it determines, and the overlapping candidate keys it hides behind
How it is assessed: Flags the deficient case and passes the acceptable one. Deficient: Arrears Assignment (Loan, Product Family, Collections Officer), key (Loan, Product Family); each officer works on one product family, so moving an officer means updating every assignment Acceptable: Collections Officer holds its Product Family; Loan Collections Assignment (Loan, Collections Officer); the constraint lost by the split goes to row 15
Also known as: Determinant that is not a key (BCNF) (logical model)
Related knobits
Builds on
Usually followed by
All 56 knobits of Derive the logical data model.
Source: Review checklist 05-logical, row 11; Codd 1974; S&W 13.3