Logical schema design goals: which targets should a good logical design meet to keep data clean, queryable, and performant?

Introduction / Context:
A logical schema describes how information is organized into entities, attributes, and relationships. A high-quality design prevents anomalies, supports intuitive queries, and enables efficient access. The question asks which goals a good logical schema should achieve.

Given Data / Assumptions:

• We are evaluating logical (not physical) design aims.
• We want data to remain consistent and reliable over time.
• We want SQL to be straightforward, and performance to be reasonable.

Concept / Approach:
Logical design aims to reduce redundancy and inconsistency (via appropriate normalization and constraints), make querying intuitive (clear table boundaries and keys), and facilitate efficient access (appropriate keys and relationships that physical design can further optimize). These goals reinforce one another; neglecting any leads to maintenance pain, slow queries, or incorrect results.

Step-by-Step Solution:

Verification / Alternative check:
Standard data modeling guidance (keys, normalization, referential integrity) explicitly targets consistency; clear schemas simplify query writing; and well-chosen keys/relations are prerequisites for physical tuning.

Why Other Options Are Wrong:

Common Pitfalls:
Over-normalizing without considering query paths, or denormalizing without constraints; both can hurt either consistency or efficiency.

Final Answer:
All of the above