Purpose of relations — evaluate the claim:\n“The only reason for the existence of relations is to store instances of functional dependencies.” Decide whether this statement is correct or incorrect.

Introduction / Context:
The relational model provides a logical structure for storing and querying data. Constraints such as functional dependencies help ensure data integrity, but they are not the sole purpose of relations.

Given Data / Assumptions:

• Relations store facts about entities and their relationships.
• Functional dependencies (FDs) describe integrity constraints among attributes.
• Normalization uses FDs (and other dependencies) to guide schema decomposition.

Concept / Approach:
A relation’s existence is justified by the need to store and retrieve consistent, meaningful data. FDs are one class of constraints used to maintain correctness and reduce redundancy. Other constraints (keys, foreign keys, check constraints), semantics (business rules), and use cases (queries, analytics, transactions) also motivate relations. Therefore, asserting that relations exist only to store FD instances is incorrect and too narrow.

Step-by-Step Solution:

Verification / Alternative check:
Consider a reporting database: tables exist primarily to store facts and dimensions; FDs inform keys and normalization but are not the reason those tables exist.

Why Other Options Are Wrong:

• “Correct only after BCNF” is misguided; even in BCNF, relations serve to store application data.
• “Performance tuning” is not the purpose of relations, though design choices affect performance.
• “Not decidable” ignores the clear conceptual separation between data storage and dependency constraints.

Common Pitfalls:
Confusing constraints (FDs) with data content; overemphasizing normalization goals at the expense of modeling needs.

Final Answer:
Incorrect — relations exist to store data about entities and relationships; FDs are constraints