Normalization
Created by Savage Killer
unnormalized data
is raw data in its original state. It might
contain redundant data, multivalued data, and/or other data
anomalies
| Term | Definition |
|---|---|
unnormalized data | is raw data in its original state. It might
contain redundant data, multivalued data, and/or other data
anomalies |
data anomaly | is an undesirable consequence of a
data modification |
Normalization | is a process that assigns attributes to entities so that data redundancies are reduced or eliminated. |
normal form | Each rule in database normalization is called |
First normal form
(1NF) | There are no repeating groups and
the primary key is identified. |
Second normal form
(2NF) | 1NF and all the columns depend on
the table’s primary key. |
Third normal form
(3NF) | 2NF and there are no non-key
attributes determined by another nonkey attribute |
Boyce-Codd normal
form (BCNF) | Every determinant is a candidate key
(special case of 3NF)
|
Fourth normal form
(4NF) | 3NF and no independent multivalued
dependencies |