relational algebra question

Question

Given two union compatible relations R1(A,B) and R2(C,D), what is the result of the operation R1 ⋈ _(A=C∨B=D)R2?

1. R1∪R2

2. R1×R2

3. R1–R2

4. R1∩R2

Comments

Thanks for answer but what is the correct option in case of OR OPERATOR?

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@Rupendra Choudhary 

may you please give any small example in this question(OR) and the other; gate question(AND)?

i am not getting and have to by heart it

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A	B
1	7
4	5
0	3

R₂ (C,D)

C	D
4	5
9	3

         

R₁∩R₂ = (4,5)

R₁∪R₂ =( (1,7),(4,5),(0,3),(9,3))

R₁ ⋈_R1.B=R2.C R₂ => No tuple

R₁ ⋈_R1.B=R2.D R₂   => ((4,5,4),(0,3,9))

R₁ ⋈_R1.A=R2.C R₂    => (4,5,5)

R₁ ⋈_R1.A=R2.D R₂     => No Tuple

R₁ ⋈_{R1.A=R2.C AND R1.B=R2.D}  R₂   => (4,5)   

R₁ ⋈_{R1.A=R2.C OR R1.B=R2.D}  R₂     => check manually like

for (1,7) if R2 has either some 1 in column name C or some 7 in column name D then 1,7 would be one tuple for o/p so apply this same concept or in other way apply R1*R2 and then our theta condition here is R1.A=R2.C OR R1.B=R2.D , so see if this condition is satisfied , then only select tuple for o/p . so (4,5,4,5), (0,3,9,3) those would be the o/p tuples..