Define the five basic relational algebra operations. Define the Join, Intersection, and Division operations in terms of these five basic operations.
What will be an ideal response?
Five basic operations are:
? Selection and Projection (Unary)
? Cartesian Product, Union, and Set Difference (Binary).
There is also the Join, Intersection, and Division operations:
? Can rewrite ?-Join in terms of the basic selection and Cartesian product operations:
R 3 F S = ?F (R ? S)
? Can express the intersection operation in terms of the set difference operation:
R ? S = R - (R - S)
? Can express the division operation in terms of the basic operations:
T 1 = ? C (R)
T 2 = ? C ( (S x T 1 ) - R)
T = T 1 - T 2
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