First normal form (1NF). Any repeating groups have been removed, so that there is a single value at the intersection of each row and column of the table.
Second normal form (2NF). Any partial functional dependencies have been removed.
Third normal form (3NF). Any transitive dependencies have been removed.
Note: If a relation meets the criteria for 3NF, [...]
Normalization is a process for converting complex data structures into simple, stable data structures.Why normalisation is necessary ?
The database design must be efficient (performance-wise).
The amount of data should be reduced if possible.
The design should be free of update, insertion and deletion anomalies.
The design must comply with rules regarding relational databases.
The design has to show pertinent [...]
Chapter Objectives
At the end of the chapter, you should be able to:
understand the purpose of normalization;
perform first, second and third normalization;
merging relations (view integration);
transforming E-R diagrams to relations.
Essential Reading
Modem Database Management (4th Edition), red R. Mcfadden & Jeffrey A. Hoffer (1994),
Benjamin/Cummings.[Chapter 6, page 199 - 237]
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