![]() ![]() State true or false: Armstrong’s axioms allow us to generate all F+ for any given FĬlarification: Armstrong’s axioms allow us to generate all F+ for any given F and hence are called complete.ĥ. This is called the reflexivity rule of Armstrong’s axioms.Ĥ. If a functional dependency is reflexive, B is a subset of A and A is the set of attributes, thenĬlarification: If a functional dependency is reflexive, B is a subset of A and A is the set of attributes, then A→B holds. It is the set of all functional dependencies logically implied by F.ģ. If F is a set of functional dependencies, then the closure of F is denoted by?Ĭlarification: If F is a set of functional dependencies, then the closure of F is denoted by F+. ![]() A functional dependency f on R is logically implied by a set of functional dependencies F on r if every instance of r(R) that satisfies F also satisfies f.Ģ. We say such FDs are logically implied by F. A functional dependency f on R is _ by a set of functional dependencies F on r if every instance of r(R) that satisfies f also satisfies F.Ĭlarification: Given a set F of functional dependencies on a schema, we can prove that certain other functional dependencies also hold on that schema. RDBMS Multiple Choice Questions on “Functional Dependency Theory”.ġ.
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