Let R and S be two relations with the following schemas. R(P. Q, R1, R2, R3) S (P. Q, S1, S2) Where {P, Q}is the key for both schemas. Which of the following queries are equivalent? 1. p (R &bowtie; S)2. p (R) &bowtie; p (S)3. p ( P , Q (R) P , Q (S) )4. p ( P , Q (R) &bowtie; P , Q (R) - P , Q (S) ) )

Let R and S be two relations with the following schemas. R(P. Q, R1, R

1.	Let R and S be two relations with the following schemas. R(P. Q, R₁, R₂, R₃) S (P. Q, S₁, S₂) Where {P, Q}is the key for both schemas. Which of the following queries are equivalent? 1. _p (R ⋈ S) 2. _p (R) ⋈ _p (S) 3. _p ( _{P , Q} (R) _{P , Q} (S) ) 4. _p ( _{P , Q} (R) ⋈ _{P , Q} (R) - _{P , Q} (S) ) )
A.	1 and 2
B.	1 and 3
C.	1, 2 and 3
D.	1, 3 and 4
Answer» E.

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Let R and S be two relations with the following schemas. R(P. Q, R1, R2, R3) S (P. Q, S1, S2) Where {P, Q}is the key for both schemas. Which of the following queries are equivalent? 1. p (R ⋈ S)2. p (R) ⋈ p (S)3. p ( P , Q (R) P , Q (S) )4. p ( P , Q (R) ⋈ P , Q (R) - P , Q (S) ) )

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