Design Objectives

1
Design Objectives

• Chapter 2

2
Design Objectives

• Why should you be concerned with database design?
• The importance of theory
• The advantages of learning good design
  methodology
• Objectives/advantages of good design
• Database design methods

3
Why should you be concernedwith database design?

• Wizards or experts are tools that should be used
  AFTER the database has beenlogically designed
• Database must insure consistency, integrity, and
  accuracy of data
• Inaccurate information is probably the most
  detrimental result of improperdatabase design.
  It can adversely affectthe bottom line of a
  business

4
Importance of theory

• Most major disciplines have theoretical base
• Structural engineers
• theories of physics
• Composers
• music theory
• Automobile designer
• Aerodynamic theory

5
Relational Database Models

• Mathematical theory
• Guarantees accurate information
• Guidelines for good design methodologies
• Not necessary to know all about mathematical
  theories to use a relational database!
• Mathematical theories provide the foundation for
  the relational database model, and thus makes the
  model predictable, reliable, and sound

6
Advantages/Objectives of good Design

• Support required and ad hoc information retrieval
• Contain efficiently constructed table structures
• Imposes data integrity at the field, table, and
  relationship levels
• Supports appropriate Business Rules
• Lends itself to future growth

7
Database design methods

• Traditional three phase method
• Requirements analysis phase
• examine business being modeled
• Data modeling phase
• modeling the database structure
• Normalization phase
• eliminate redundant data