Question Discussion & Solution

🔑 Key Points

• A table is in Third Normal Form (3NF) if it is in 2NF and there are no transitive dependencies for non-prime attributes on a candidate key.
• A transitive dependency occurs when a non-prime attribute (C) is functionally dependent on another non-prime attribute (B), which in turn is functionally dependent on the candidate key (A) (i.e., \( A \rightarrow B \) and \( B \rightarrow C \) imply \( A \rightarrow C \)).
• 3NF ensures that all non-key attributes are directly dependent on the primary key, not on other non-key attributes.
• This helps to further reduce redundancy and improve data integrity.

📄 Additional Information

• To achieve 3NF, the table is decomposed, and the transitively dependent attributes are moved to a new table with the intermediate non-key attribute as its primary key.
• For example, if 'Student ID' determines 'Department ID', and 'Department ID' determines 'Department Name', then 'Student ID' transitively determines 'Department Name'. This violates 3NF.
• Partial dependency is addressed by Second Normal Form (2NF).