Normalization and 1NF

Normalisation is:

• Removing all necessary data from a database

• Organising a database to remove repeated entries and increase the accuracy of the data

• Putting fields from different tables into one big database

An advantage of normalisation is:

• The storage space needed for a normalised database is likely to be smaller

• The process of normalising a database is very easy and doesn’t require any skill

• It is possible to see previous details that have been changed, such as a customer’s address, as we can look back at an older entry

A disadvantage of normalisation is:

• The data loses its integrity as some of it is removed in the normalisation process

• The process of searching the database may be slower due to a higher demand on the central processing unit (CPU)

• Removing redundant data means that links cannot be created between tables

What is an atomic field?

• A field that contains multiple items of data

• A field that is repeated

• A field that contains only one item of data

What is a foreign key?

• A unique identifier in a database

• A primary key of one table that appears in another table

• A field that should not be in a table and needs removing

A relation is in 1NF if it doesn't contain any ____________?

• Determinants

• Repeating groups

• Null values in primary key fields

• Functional dependencies

When you normalize a relation by breaking it into two smaller relations, what must you do to maintain data integrity?

• Remove any functional dependencies from both relations

• Assign both relations the same primary key field(s)

• Create a primary key(s) for the new relation

When designing a database you should ____.

• make sure entities are in normal form before table structures are created

• create table structures then normalize the database

• only normalize the database when performance problems occur

• consider more important issues such as performance before normalizing

The normalization process involves assigning ____ to tables based on the concept of determination.

• data

• files

• attributes

• relations

A ____ key is an artificial PK introduced by the designer with the purpose of simplifying the assignment of primary keys to tables.

• surrogate

• composite

• candidate

• foreign