Chapter 2 (True/False)

A data model is usually graphical.

2. An implementation-ready data model needn't necessarily contain enforceable rules to guarantee the integrity of the data.

3. An implementation-ready data model should contain a description of the data structure that will store the end-user data.

4. Within the database environment, a data model represents data structures with the purpose of supporting a specific problem domain.

5. Even when a good database blueprint is available, an applications programmer’s view of the data should match that of the manager and the end user.

6. In the context of data models, an entity is a person, place, thing, or event about which data will be collected and stored.

7. Database designers determine the data and information that yield the required understanding of the entire business.

8. Business rules apply to businesses and government groups, but not to other types of organizations such as religious groups or research laboratories.

9. Business rules must be rendered in writing.

10. In an SQL-based relational database, each table is dependent on every other table.

11. In an SQL-based relational database, rows in different tables are related based on common values in common attributes

12. A disadvantage of the relational database management system (RDBMS) is its inability to hide the complexities of the relational model from the user.

13. Each row in the relational table is known as an entity instance or entity occurrence in the ER model.

14. In Chen notation, entities and relationships have to be oriented horizontally; not vertically.

15. M:N relationships are not appropriate in a relational model.

16. Today, most relational database products can be classified as object/relational.

17. The network model has structural level dependence.

18. The external model is the representation of the database as “seen” by the DBMS.

19. The hierarchical model is software-independent.

20. The relational model is hardware-dependent and software-independent.