Muhammad Umair

Normalization

Oracle Database 11g Developer Track

Normalization

› Normalization– A process of minimizing data redundancy/duplication from

relation/tables

Normalization

› Simple Dependency/ Functional Dependency– All attribute are depends on Primary key

› Partial Dependency– Some attribute are dependent on part of primary key

› Transitive Dependency– Dependency of an attribute on Primary key through

another attribute› Multi-valued Dependency

– If two or more multi-valued attributes are merged in one relation then that relation will be hold multi-valued dependency

Normalization

› Normalization– A process of minimizing data redundancy/duplication from

relation/tables– Normalization is used for verification of tables/relations

› Anomalies– The problem of un-normalized database can be

– Insertion anomalies– Modification anomalies– deletion anomalies

Normalization

› Normal Form– In normalization process we have to check our

relation/tables against some standards. Each of those standards are called a “Normal Form”

› First Normal Form : 1NF– A table will be in 1NF if no repeating group/ Multi-valued

attribute exists in it.› Second Normal Form : 2NF

– A table will be in 2NF if it is already in 1NF and no partial dependency exists in it.

Normalization

› Third Normal Form : 3NF– A table will be in 3NF if it is already in 2NF and no

transitive dependency exists in it.› Fourth Normal Form : 4NF

– A table will be in 4NF if it is already in 3NF and no multi-valued dependency exists in it.