Normalisation

Question 1

What is the purpose of normalisation?

Answer 1

To eliminate redundant data

Question 2

Define “first normal form”

Answer 2

First normal form requires all Types to be atomic; i.e. no “lists” of items are allowed.

Question 3

Define “second normal form”

Answer 3

Removes partial dependencies on the primary key (only for composite primary keys). So all elements have to be dependant on the whole primary key.

Question 4

Define “third normal form”

Answer 4

Removes Transitive Functional Dependencies - so nothing like this:

A→B→C in the same table.

Instead would have:

Table 1: A→B

Table 2: B→C

Question 5

Define “Boyce-Codd Normal Form”

Answer 5

Eliminates dependencies on attributes that are not superkeys