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What Is Functional Dependency? |
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Answer» A Functional DEPENDENCY is denoted by X Y between two sets of attributes X and Y that are subsets of R specifies a constraint on the possible tuple that can FORM a relation STATE r of R. The constraint is for any two tuples TI and T2 in r if tl[XJ = t2[Xj then they have tl[Y] = t2[Y]. This means the value of X component of a tuple uniquely determines the value of component V. A Functional dependency is denoted by X Y between two sets of attributes X and Y that are subsets of R specifies a constraint on the possible tuple that can form a relation state r of R. The constraint is for any two tuples ti and t2 in r if tl[XJ = t2[Xj then they have tl[Y] = t2[Y]. This means the value of X component of a tuple uniquely determines the value of component V. |
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