Database Normalization 1NF-3NF

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

Which of the following statements fully describes data in 2NF:

• When any repeating fields have been removed and the table is given a primary key

• When all repeating entries of data are removed and the fields in each table are directly related to the primary key and no fields are present that are not related to each other

• When all the fields in each table are directly related to the primary key

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

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

• Determinants

• Repeating groups

• Null values in primary key fields

• Functional dependencies

A table is in 2NF if the table is in 1NF and what other condition is met?

• There are no functional dependencies.

• There are no null values in primary key fields.

• There are no repeating groups.

• There are no attributes that are not functionally dependent on the relation's primary key.

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

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

Tables in ____ will perform suitably in business transactional databases.

• 0NF

• 1NF

• 2NF

• 3NF

A table where all attributes are dependent on the primary key and are independent of each other, and no row contains two or more multivalued facts about an entity, is said to be in ____.

• 1NF

• 2NF

• 3NF

• 4NF

A table in ____ contains no transitive dependencies.

• 1NF

• 2NF

• 3NF

• none of the above