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To do the division operation R1 ÷ R2, R2 should be a correct subset of R1. In the following example R1 have attributes A and B and R2 have only attribute B so R2 is a correct subset of R1. If we perform R1 ÷ R2 than the resultant relation will have those values of A from R1 that are related to all values of B present in R2.
Example
A
B
A1
B1
B2
A2
A3
A4
A5
Let R1
If R2 R3= R1 ÷ R2 If R2 R3= R1 ÷ R2
Figure: The Division Operation
Note:
Degree of relation: Degree (R ÷ S)=Degree of R - Degree of S.
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