Saturday, 27 September 2014

Compare 2NF and 3NF


Difference between 2NF and 3NF / Comparison of 2NF and 3NF / Compare 2NF and 3NF / 2NF and 3NF Comparison / Differentiate 2NF and 3NF




Properties to be satisfied for 2NF and 3NF (recall)


2NF – Table should be in 1NF and no partial functional dependency presents.
3NF - Table should be in 2NF and Every non-prime attribute of R is non-transitively dependent on every superkey of R. 

Properties
2NF
3NF
Attribute Domain
Should be Atomic
Should be Atomic
Functional Dependencies Identification
Must
Must
Handling of Update Anomalies
Handle update anomalies
Handle update anomalies.
Partial Dependencies
Not permitted
Not permitted
Transitive Functional Dependency
Can be permitted
Cannot be permitted
Goal
Eliminate Redundant Data
Ensure Data Dependencies
 

 

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