Database Design Chapter 3

9. State the difference between a key and an index

Keys are part of the logical structure of a database used to identify records and Indexes are physical structures used to optimize data processing but are not in the table.

2. Name the four categories of terms

Value-related, structure-related, relationship-related, and integrity-related.

13. What three types of elements does a field specification incorporate?

General elements, Physical elements, and Logical elements.

8. What is a view?

A "virtual" table that is comprised of fields from different tables.

4. What does null represent?

A missing or unknown value.

11. What are the three ways in which you can characterize a relationship?

By the type of relationship that exists between tables, the manner in which each table participates, and the degree to which each table participates.

7. Name the three types of tables

Data Table, Validation Table, and (Virtual Table? (View)?)?

3. What is the difference between data and information?

Data is values without context. Information is data put into context that is used to understand it.

10. What are the three types of relationships that can exist between a pair of tables?

One-to-One, One-to-Many, and Many-to-Many.

12. What is a field specification?

Represents all the elements of a field.

15. Name the four types of data integrity.

Table-level integrity (entity), Field-level integrity (domain), Relationship-level integrity (referential), and Business Rules.

6. What are the chief structures in the database?

Tables

14. What is data integrity?

The validity, consistency, and accuracy of the data in a database.

1. Why is terminology important?

They are used to express and define the special ideas and concepts of the relational database model. They are used to express and define the database design process itself. They are used anywhere a relational database or RDBMS is discussed.

5. What is null's major disadvantage?

They do not work with mathematical operations because if there is a null in the problem then the answer is always "null".