Database Design
The Database Schema
- Transforming the logical data model into a physical relational database schema rules and guidelines: (continued)
- Supertype/subtype entities present additional options as follows:
- Most CASE tools do not currently support object-like constructs such as supertypes and subtypes.
- Most CASE tools default to creating a separate table for each entity supertype and subtype.
- If the subtypes are of similar size and data content, a database administrator may elect to collapse the subtypes into the supertype to create a single table.
- Evaluate and specify referential integrity constraints.