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self doubt

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If there are no attributes in common between two relations R and S then, what should be the result of (R natural join S)?

1) R x S

2) $\phi$

I think option 2 because of following definition from Korth:

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Option a is correct ,

If there are no common attribute between Relation R and S then natural join degrades to cartesian product .

Option b would have been correct , if there was a common attribute Atribute and none of tuple would have same value for that attribute

Hence the answer is option 1 :)
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