Chapter 7, Problem 10PE

Explanation of Solution

Lossless join decomposition:

A decomposition $\left\{\text{R1,R2}\right\}$ is known to be lossless join decomposition when the relation $\text{R1}\cap \text{R2}\to \text{R1}$ or $\text{R1}\cap \text{R2}\to \text{R2}$.

Things that could go wrong on violation:

• The value of the attribute that is present at the left hand side of the function dependency for lossless decomposition cannot be null.
• If the values of the attributes are null then the resultant of the decomposition will be lossy in nature