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10 Cards in this Set
- Front
- Back
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Functional Dependencies |
X defines Y if for every pair of tuples T1 and T2 in r if T1.X=T2.X, then T1.Y=T2.Y |
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* Update anomalies
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updating one without updating another |
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Insertion anomalies |
not having all the data necessary to insert |
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Deletion anomalies |
* deleting more information than desired
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Solution to redundency issues |
decomposition |
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Second Normal Form |
* all its nonkey attributes are dependent upon all of the key
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* Third Normal Form
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* in second normal form and has no transitive dependencies
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* Boyce-Codd Normal Form
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* if every determinant is a candidate key
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* Fourth Normal Form
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if BCNF and has no multivalued dependencies |
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Essence of normalization |
every normalized relation has a single theme |
