Consider the relations R(A,B) and S(B,C) and the following four relational algebra queries over R and S: I. πA,B(R⋈S) II. R⋈πB(S) III. R∩(πA(R) Χ πB(S)) IV. πA,R.B(R Χ S) where R.B refers to the column B in table R. One can determine that: (A) I, III and IV are the same query. (B) II, III and IV are the same query. (C) I, II and IV are the same query. (D) I, III and III are the same query.

Consider the relations R(A,B) and S(B,C) and the following four relational algebra queries over R and S:

I. πA,B(R⋈S)

II. R⋈πB(S)

III. R∩(πA(R) Χ πB(S))

IV. πA,R.B(R Χ S) where R.B refers to the column B in table R.

One can determine that:

(A) I, III and IV are the same query.

(B) II, III and IV are the same query.

(C) I, II and IV are the same query.

(D) I, III and III are the same query.
by

1 Answer

Answer :

(D) I, III and III are the same query.
by

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