Question

Difference Between Lossy and Lossless Decomposition
Distinguish between lossy and lossless decomposition as used in normalization?

Answer 1

Lossy Decomposition is the relation R in the R1 and R2 when the R1 and R2 joint does not yield the same relation as in the R.

Lossless Join Decomposition is the relation R in the R1 and R2 when the R1 and R2 yield the same relation that is in the R.

Answer 2

Answer:

We we do decomposition it removes redundancy and inconsistencies from a database by dividing the table into multiple tables.

They are of two types :

Lossless Decomposition

A Decomposition is lossless if it is feasible to reconstruct relation R from decomposed tables using Joins. The join would result in the same original relation R.

Lossy Decomposition

As the name lossy , when a relation is decomposed into two or more relational schemas, there is a loss of information when the original relation is retrieved in case of lossy decomposition.