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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
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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 • 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: