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Explain the Cartesian product:
The Cartesian product operation does not need relations to union-compatible. The meaning of this is that the involved relations may have dissimilar schemas. Let R & S be relations that may have dissimilar schemas.
DEF: Cartesian product
The Cartesian product of relations R and S, denoted R X S, is the set of all probable combinations of tuples of the two operation relations. Every resultant tuple contains all the attributes of R and S.
The resultant relation has
Cardinality = (cardinality of R) * (cardinality of S); and
arity = (arity of R) + (arity of S).
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