Normalization

Normalisation is:

• Removing all necessary data from a database

• Putting fields from different tables into one big database

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

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 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 attributes that are not functionally dependent on the relation's primary key.

• There are no repeating groups.

. 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

. 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

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

To be in 1NF:

• Each field contains the smallest meaningful value

• There are multiple values in the single field

• There are no duplicate records

• A primary key is assigned

Which one of these do you want to avoid in good database design?

• Redundancy!

• Giant squid!

• Third normal form!

• Data!