Normalisation

Question 1

When to go to 2NF?

Answer 1

Only when PK is made up of >1 column

Question 2

What is 1NF?

Answer 2

Enforces the rule is that each cell can only contain a single value from the correct domain

Question 3

What is 2NF?

Answer 3

A table in which the values of each non-PK column are determined by the values in all the columns that make up the PK

Question 4

How to test if table is in 2NF?

Answer 4

1. Identify the composite PK columns
2. Check for any non-PK columns that have only partial functional dependency on the PK

Question 5

Full Functional Dependency

Answer 5

All PK column values to determine the value in a non-PK column

Question 6

Partial Functional Dependency

Answer 6

If any subset of PK columns always maps to the same value

Question 7

What is 3NF?

Answer 7

A table in which the values in all non-PK columns can only be determined from the PK columns and no other columns

Question 8

Transitive dependency

Answer 8

Occurs when a non-PK column is functionally dependent on another non-PK column