Schema mapping reality check: Evaluate the statement: "There is one physical schema for each logical schema."

Introduction / Context:
Logical schemas describe what data represent and how they relate, independent of storage details. Physical schemas describe how the data are stored and accessed (files, partitions, indexes, clustering). This question tests whether you understand that the mapping between logical and physical schemas is not one-to-one.

Given Data / Assumptions:

• Logical design is technology-agnostic.
• Physical design can vary by performance, scale, and operational constraints.
• Multiple physical realizations might exist for different workloads (OLTP vs. OLAP).

Concept / Approach:
A single logical schema can be implemented as multiple physical schemas to suit different use cases (e.g., normalized OLTP vs. denormalized star schema in analytics). Conversely, multiple logical views can be presented over a single physical schema via views or semantic layers. Therefore, claiming exactly one physical schema per logical schema is inaccurate.

Step-by-Step Solution:

Verification / Alternative check:
Examine organizations that maintain operational stores and warehouses/lakes implementing the same logical entities differently.

Why Other Options Are Wrong:

• Limiting truth to normalization level, cloud, or denormalization ignores the general many-to-many relationship between logical and physical designs.

Common Pitfalls:
Expecting a single physical design to satisfy all workloads; skipping performance modeling before choosing access paths.

Final Answer:
Incorrect