Another algebraic way to express a constraint is E1 E2 whe

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Another algebraic way to express a constraint is E_1 = E_2, where both E_1 and E_2 are relational-algebra expressions. Can this form of constraint express more than two forms ? Suppose R is a relation with attributes A_1, A_2, ...., A_n

Solution

Q3) Suppose R is a relation with attributes A1,A2,............,An

Answer:-

Number of combinations of attributes that contains {A1}, {A2} or {A1,A2}: 3 * 2^{n-2} .