Normalisation

Question 1

what is a normal form

Answer 1

a way of organising data in a table within a database

Question 2

what is normalisation

Answer 2

the process of arranging tables based on critearia of each form

Question 3

what has to be done to get to the first normal form

Answer 3

• eliminate duplicate columns
• get rid of any groups repeating data
• identify primary key
• seperate non atomic attributes

Question 4

what is a composite key

Answer 4

a key that uses multiple attributes to distinguish the data

Question 5

what has to be done to get to the second normal form

Answer 5

• check data is in the first normal form
• remove any partial dependecies (when data only relies on part of a composite key), fixed by splitting the data into new tables
• fix any many to many relationships

Question 6

what has to be done to get to the third normal form

Answer 6

• check that the data is in second normal form

- make sure there are no non key dependencies where attributes are determined with out the use of the key