Explain the steps to create a physical model from a logical model. Identify the high‑level entities, break them down, and establish relationships. Which normal form is generally enforced in the physical model, and at what level of normalization is this done?

The process begins with a logical model, which captures business concepts as entities, attributes, and relationships. First, identify the high‑level entities that represent real‑world objects (e.g., Customer, Order, Product). Next, decompose each entity into atomic attributes, ensuring each attribute holds a single value. Define primary keys for each entity and establish foreign keys to represent relationships. Once the logical schema is stable, move to the physical model: map entities to tables, attributes to columns, and enforce data types and constraints. During this translation, apply normalization rules to eliminate redundancy. The physical model is typically designed to 3NF, which removes transitive dependencies and ensures that non‑key attributes depend only on the key. In some cases, designers may apply 4NF to handle multi‑valued attributes, but this is uncommon for standard OLTP systems. After normalization, performance tuning (indexing, partitioning) is added to meet application requirements.