LOSSLESS JOIN DECOMPOSITION

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Normalization is the process of minimizing redundancy and eliminating anomalies from a relation or a set of relations.
 Decomposition of a relation is done when a relation is not in required normal form .
 
We can decompose a relation into two or more relations if decomposition is lossless join as well as dependency preserving.

 Upto 3rd normal form both of these decomposition properties we need to preserve. 

Given a relation R after decomposing R into R1 and R2  ,


If R1 join R2 =R ,then the decomposition is said to be lossless join decomposition .


If R1 join R2 is ⊃ R ,then the decomposition is said to be lossy decomposition .








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