BTEC National ICT U2 - 1st Normal Form

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

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

A primary key

• Is a unique identifier for the table. It cannot be null. 
• Is a unique identifier for the table. It can be null. 
• Is an identifier that always connects to a foreign key. 
• Is used in flat file databases. 

Entities (tables) have attributes (fields). 

• True
• False

Which of these are required for a relational database to meet 1st normal form?

• Data must be atomic

• No repeating groups of data

• No repeating attributes

• Sets of data must have a unique identifier

• Must meet 2nd normal form

What is the purpose of normalisation?

• Eliminate redundant data

• Reduce data inconsistencies

• Produce redundant data

• Increase data inconsistencies

Which type of relationship does the ERD represent?

• One-to-many

• Many-to-many

• One-to-one

An attribute is represented by what in a database?

• Table

• Row

• Column

• Cell

Which type of relationship does the ERD represent?

• One-to-many

• Many-to-many

• One-to-one