Question

consider two relations r1 and r2.pick the correct operations from the following that compute the relation having the set of attribute belonging to relation r1 and not belonging to relation r2.

Answer 1

Consider two relations r1 and r2.pick the correct operations from the following that compute the relation having the set of attribute belonging to relation r1 and not belonging to relation r2.

There are Relations

AND   1+1 = 1  rest all 0

OR    0 +0 =0 rest all 1

NOT 1 = 0  and 0 =1

To find relation where r1 is complete but not r2

r1 OR (NOT(r2))

Answer 2

Set Difference Operation:

If R₁ and R₂ are two relations then the result of this operation denoted by R₁ - R₂, is a relation that includes all the tuples that are there in R₁ but not in R₂.

Example:

Select * from R₁ where (name, eno) not in (select * from R₂).

Hope it helps!