Free Keys, ER and normalization lessonsKeys, ER and normalization · Stage 2 · Functional dependencies · Step 2
Finding candidate keys
Use closure to find every candidate key of a relation, with the shortcut of attributes that never appear on a right side. About 14 minutes.
For R(A, B, C) with FDs A → B and B → C, what is the candidate key?
- A{A}
- B{B}
- C{A, B, C}
Show the answer
{A}. A appears on no right side, and {A}⁺ = ABC.
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