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3rd Normal Form
The database is now in 3rd normal form. There are no longer any transitive dependencies and 1st and 2nd normal forms have been observed. A new manufacturer table has been created with eqpt_mfgr as the primary key. Mfgr_addr has been moved into this table.
Summary
We have normalized out original spreadsheet by
- Removing all non-atomic cells or repeating groups
- Removing partial key dependencies
- Removing transitive dependencies
Additonal Normal Forms
Definition
There are three additional normal forms.
- Boyce-codd which is a variation on 3rd normal form.
- 4th which addresses multi-valued attributes in composite primary keys.
- 5th or domain/key normal form which states all columns are dependent solely on the key and in particular the entire key.
Futures
We may look at these in future articles or an extension to this one.
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