1. Chapter 3
The Relational Model

2. Agenda
Concept
Property
Key
Integrity Constraint
Base Relation & View

3. Concept Relation Attribute Domain Tuple Degree Cardinality
Relational Database

4. Property Unique relation name Unique attribute No duplication tuples
No repeating group (single value for an attribute)
Same domain for an attribute
Insignificance of the tuples or attributes order

5. Key
Superkey
Candidate key (Alternative key)
Primary key
Foreign key

6. Integrity Constraint Null Integrity constraint Entity Reference
Domain (edit or field)
Enterprise (business rule)

7. Base Relation & View Base relation View Purpose of views
A named relation of an entity in conceptual schema
Tuples stored in physical database
View
Virtual relation
Dynamic generated for end user
Not stored in the physical database
Purpose of views
Security
User friendly report
Performance

8. Points To Remember Concept Property Key Integrity Constraint
Base Relation & View

9. Assignment Review chapters 1-3, & appendix c
Read Chapter 4 (skip relational calculus 4.2)
Do Exercise 3.8
Due date: