1. No duplication of data leads to…
1. Easier to update and change data, as changes will only need to occur in one field.
2. Maintaining data integrity, and removes the possibility of one record having two different values for attributes.
2. Having smaller tables with fewer fields...
1. Means faster queries.
2. Means more data can fit inside the same amount of space

Many-to-Many relationships.

Split an entity into two relations.

Many-to-many relationships.

Introduce link tables.

A relation with all of the attributes being both foreign keys of other relations and composite primary keys of itself.

Where an entity has a composite primary key and another attribute is dependent on only one of the attributes that make up the primary key.

Where an attribute is not dependant on the primary key.

1. No-non atomic fields.
2. No repeating sets of data.

1. No-non atomic fields.
2. No repeating sets of data.


3. No partial key dependencies.

1. No-non atomic fields.
2. No repeating sets of data.


3. No partial key dependencies.


4. No non-key dependencies.