Made Easy Test Series

Question

Answer 1

/ operation on relation R/S returns all the attributes of R – attributes of S. The tuples include all the tuples of R that are mapped to the tuples of S with the common attribute.

Now coming to this question:
sid,cid/cid => this will only return sid
π cid ( σ <condition> (Course) ==> returns
|cid|
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(empty table)

 

now after division, all the tuples of R mapped to the above tuples of the table will get returned. As nothing is returned, no tuple of R can be mapped, hence the resultant will also be 0 tuples

 

therefore the answer is 0.

 

I tried to explain the best I could. Hope it was helpful

Comments

Did ME reply to your query? 😐

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@ankit3009 Seriously, does that matter?

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No @Arjun Sir, it doesn't matters until and unless the explaination comes from someone who have gained the expertise as you have in this field. 😁 Thanks for the Gate overflow!