Chapter 3

   

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1:	Why is terminology important?
A1:	Terminology is important for the following reasons: It is used to express and define the special ideas and concepts of the relational database model. It is used to express and define the database-design process itself. It is used anywhere a relational database or RDBMS is discussed.
2:	Name the four categories of terms.
A2:	The four categories of terms are value- related , structure-related , relationship-related , and integrity-related .
3:	What is the difference between data and information ?
A3:	The values you store in the database are data . Information is data that you process in a manner that makes it meaningful and useful to you when you work with it or view it.
4:	What does a null represent?
A4:	A null represents a missing or unknown value.
5:	What is a null's major disadvantage ?
A5:	The major disadvantage of nulls is that they have an adverse affect on mathematical operations.
6:	What are the chief structures in the database?
A6:	Tables are the chief structures in the database.
7:	Name the three types of tables.
A7:	The three types of tables are data tables, linking tables, and validation tables.
8:	What is a view ?
A8:	A view is a virtual table composed of fields from one or more base tables in the database.
9:	State the difference between a key and an index .
A9:	A key is a logical structure that you use to identify records within a table, and an index is a physical structure that you use to optimize data processing.
10:	What are the three types of relationships that can exist between a pair of tables?
A10:	The three types of relationships that can exist between a pair of tables are one-to-one , one-to-many , and many-to-many .
11:	What are the three ways in which you can characterize a relationship?
A11:	You can characterize every relationship in three ways: by the type of relationship that exists between the tables, the manner in which each table participates, and the degree to which each table participates.
12:	What is a field specification ?
A12:	A field specification represents all the elements of a field.
13:	What three types of elements does a field specification incorporate ?
A13:	A field specification incorporates three types of elements: general , physical , and logical .
14:	What is data integrity ?
A14:	Data integrity refers to the validity, consistency, and accuracy of the data in a database.
15:	Name the four types of data integrity.
A15:	The four types of data integrity are field-level , table-level , relationship-level , and business rules .

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