This document summarizes key concepts about database normalization from Chapter 5. It defines relations, functional dependencies, keys, and discusses normal forms including 1NF, 2NF, 3NF and BCNF. Anomalies that can occur are defined. The goal of normalization is to reduce anomalies by converting relations into higher normal forms through decomposition. Relationships between attributes are classified as one-to-one, many-to-one, or many-to-many. Optimization techniques like de-normalization and controlled redundancy are also covered.

1. Database Processing
Chapter 5
The Relational Model and
Normalization
David M. Kroenke
© 2000 Prentice Hall

2. Chapter 5
The Relational Model
• Broad, flexible model
• Basis for almost all DBMS products
• E.F. Codd defined well-structured
“normal forms” of relations,
“normalization”
Page 113
© 2000 Prentice Hall

3. Chapter 5
Relation
• Two-dimensional table
• Rows are tuples
• Columns are attributes
Page 113
© 2000 Prentice Hall

4. Equivalent Relational Terms
Page 114
Figure 5-1 © 2000 Prentice Hall

5. Functional Dependency
“relationship between or among
attributes”
Page 114
Figure 5-2 © 2000 Prentice Hall

6. Chapter 5
Functional Dependency
Notation
SID  Major
ComputerSerialNumber  MemorySize
(SID, ClassName)  Grade
Page 115
© 2000 Prentice Hall

7. Key
“a group of one or more attributes that
uniquely identifies a row”
Page 116
Figure 5-3 © 2000 Prentice Hall

8. Combination Key
Page 117
Figure 5-4 © 2000 Prentice Hall

9. Chapter 5
Normalization
“the process of evaluating and
converting a relation to reduce
modification anomalies”
Page 118
© 2000 Prentice Hall

10. Chapter 5
Anomaly
“an undesirable consequence of data
modification in which two or more
different themes are entered
(insertion anomaly) in a single row or
two or more themes are lost if the
row is deleted (deletion anomaly)”
Page 118
© 2000 Prentice Hall

11. Chapter 5
Normal Forms
“classes of relations and techniques for
preventing anomalies”
DK/NF = Domain Key Normal Form
(free of modification anomalies)
Page 118
© 2000 Prentice Hall

12. First Normal Form
“any table of data that meets the
definition of a relation”
Figure 5-3 © 2000 Prentice Hall

13. Second Normal Form
“when all of a relation’s nonkey attributes
are dependent on all of the key”
Figure 5-5 © 2000 Prentice Hall

14. Third Normal Form
“if it is in second normal form and has
no transitive dependencies”
Figure 5-7 © 2000 Prentice Hall

15. Boyce-Codd Normal Form
“if every determinant is a candidate key”
Figure 5-8 © 2000 Prentice Hall

16. Fourth Normal Form
“if in BCNF and has no multi-value
dependencies”
Figure 5-11 © 2000 Prentice Hall

17. Chapter 5
Fifth Normal Form
?
Page 125
© 2000 Prentice Hall

18. Chapter 5
Domain Key Normal Form
“if every constraint on the relation is a
logical consequence of the definition
of keys and domains”
Page 125
© 2000 Prentice Hall

19. Chapter 5
DK/NF Terms
• Constraint “a rule governing static
values of attributes”
• Key “unique identifier of a tuple”
• Domain “description of an
attribute’s allowed values”
Page 126
© 2000 Prentice Hall

20. DK/NF Example
Figure 5-13 © 2000 Prentice Hall

21. DK/NF Example
Figure 5-15 © 2000 Prentice Hall

22. DK/NF Example
Figure 5-16 © 2000 Prentice Hall

23. Summary of Normal Forms
Figure 5-18 © 2000 Prentice Hall

24. Chapter 5
A  B relationships
A  B and B  A one-to-one
A  B but B not  A many-to-one
A not  B and B not  A many-to-many
Page 131
© 2000 Prentice Hall

25. Summary of Relationships
Figure 5-19 © 2000 Prentice Hall

26. Chapter 5
Optimization
• De-Normalization
• Controlled Redundancy
Page 135
© 2000 Prentice Hall