Features of physical data model include:
• Specification all tables and columns.
• Foreign keys are used to identify relationships between tables.
• De-normalization may occur based on user requirements.
• Physical considerations may cause the physical data model to be quite different from the logical data model.
At this level, the data modeller will specify how the logical data model will be realized in the database schema.
The steps for physical data model design are as follows:
1. Convert entities into tables.
2. Convert relationships into foreign keys.
3. Convert attributes into columns.
4. Modify the physical data model based on physical constraints / requirements.