Chapter 3 The Relational Model
Agenda Concept Property Key Integrity Constraint Base Relation & View
Concept Relation Attribute Domain Tuple Degree Cardinality Relational Database
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
Key Superkey Candidate key (Alternative key) Primary key Foreign key
Integrity Constraint Null Integrity constraint Entity Reference Domain (edit or field) Enterprise (business rule)
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
Points To Remember Concept Property Key Integrity Constraint Base Relation & View
Assignment Review chapters 1-3, & appendix c Read Chapter 4 (skip relational calculus 4.2) Do Exercise 3.8 Due date: