Chapter 2, Problem 4TD

Program Plan Intro

Functional dependency:

• A column “X” is said to be functionally dependent on another column “Y”, when at any point of time, a value for “X” determines a single value for “Y”.
• In other words, a column “X” is said to be functionally dependent on another column “Y”, when two tuples agree on attribute “X” values then they should also agree on attribute “Y” values.
• It is usually represented as “XY”, where the terms “X” and “Y” are composite.
• It can be said as either “Y” is functionally dependent on “X” or as “X” functionally determines “Y”.

Normalization:

• Normalization refers to the method of representing a database in the terms of relations, which are in the standard normal forms.
• It is organized in a table manner to reduce data redundancy and data dependency.

Third Normal Form (3NF):

A table or a relation is said to be in third normal form if and only if it is in second normal form and if the candidate keys are its only determinants.