Chapter 7, Problem 22E

Explanation of Solution

Lossless, dependency preserving decomposition of schema “R” into third Normal Form (3NF):

• Let schema R=(A,B,C,D,E) has been decomposed into (A,B,C) and (D,E,F).
• To decompose relation schema into 3NF, a canonical cover is used.
• The designs which are both lossless and dependency preserving can be produced by this algorithm.
• This algorithm is given in the Figure 7.12 of the textbook.
• The four functional dependencies given in the question forms a canonical cover.
• To get the relation (A,B,C) , use the functional dependency $\text{A}\to \text{BC}$.
• Get the relation (C,D,E) from functional dependency $\text{C}\to \text{DE}$