Final answer:
Converting an extended E-R model to a relational database design involves creating tables from entities and relationships, establishing primary and foreign keys, handling complex attributes, and managing extended features like inheritance. A conversion table can help track the transformation process.
Step-by-step explanation:
The process of converting an extended Entity-Relationship (E-R) model into a relational database design typically involves several systematic steps. First, entities and relationships are converted into tables. Entities become tables with rows representing instances of that entity and columns representing attributes. Primary keys are designated for each table to ensure each record can be uniquely identified.
Next, relationships in the E-R model are converted into foreign keys in the appropriate tables, establishing the needed links between them as per the relationship cardinality and constraints. Complex attributes are handled by creating separate tables or by integrating them into existing tables with careful design considerations.
When it comes to extended features such as inheritance in the E-R model, these are translated into relational tables through strategies like creating a single table for the entire hierarchy, individual tables for each subclass, or a combination of both. The decision depends on factors like query performance and complexity of the model.
It is often helpful to create a conversion table or a mapping document during this process to keep track of how each E-R model element is converted into the relational schema. This table can serve as a reference for understanding and verifying the transformation process.