Are relations categorized into normal forms because of their referential integrity constraints (foreign-key relationships)?

Introduction / Context:
Normalization organizes relations to reduce redundancy and prevent anomalies. This question checks whether normal forms are defined by referential integrity constraints (foreign keys) rather than by functional and multivalued dependencies.

Given Data / Assumptions:

• Normal forms like 1NF, 2NF, 3NF, and BCNF are defined using keys and functional dependencies.
• Higher forms like 4NF involve multivalued dependencies; 5NF involves join dependencies.
• Referential integrity constraints ensure cross-table consistency but are not the basis for normal form definitions.

Concept / Approach:
2NF removes partial dependency on a candidate key, 3NF removes transitive dependency on a candidate key, and BCNF strengthens the determinant requirement. None of these definitions depends on foreign keys. Foreign keys are orthogonal constraints ensuring that referenced values exist in parent tables.

Step-by-Step Solution:

Verification / Alternative check:
Look up formal definitions of normal forms—their statements reference dependencies, not referential integrity rules.

Why Other Options Are Wrong:

• “Correct” confuses two distinct areas: normalization (dependencies) vs. referential integrity (relationships between tables).
• Mentions of BCNF or indexing foreign keys are irrelevant to the defining criteria.

Common Pitfalls:
Assuming that because normalization often introduces foreign keys, the forms are defined by them. The definitions remain dependency-based.

Final Answer:
Incorrect