Rules of Data Normalization
Rules of Data Normalization
1NFEliminate Repeating Groups - Make a separate table for each set of related attributes, and give each table a primary key.
2NFEliminate Redundant Data - If an attribute depends on only part of a multi-valued key, remove it to a separate table.
3NFEliminate Columns Not Dependent On Key - If attributes do not contribute to a description of the key, remove them to a separate table.
BCNFBoyce-Codd Normal Form - If there are non-trivial dependencies between candidate key attributes, separate them out into distinct tables.
4NFIsolate Independent Multiple Relationships - No table may contain two or more 1:n or n:m relationships that are not directly related.
5NFIsolate Semantically Related Multiple Relationships - There may be practical constrains on information that justify separating logically related many-to-many relationships.
ONFOptimal Normal Form - a model limited to only simple (elemental) facts, as expressed in Object Role Model notation.
DKNFDomain-Key Normal Form - a model free from all modification anomalies.
http://www.datamodel.org/NormalizationRules.html
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