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Define the Division Operation of Relational Algebra
Let R be a relation comprising attributes (A1,...Ap,Ap+1,...An) and S comprising attributes (Ap+1,...An)
DEF: Division
The division of R by S, represented R ÷ S, provides a new relation Q, the quotient of the division, like Q has attributes (A1...Ap) and every tuple of Q must take place in R in combination along with every tuple in S.
The division can be acquired from the difference, the Cartesian product and the projection like this:
R ÷ S = T - Y, where T = πA1,...Ap (R ) and Y = πA1,...Ap ( (T X S) - R)
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