Master SQL Development (LinkedIn)

Question 1

Describe Normalization

Answer 1

The process of organizing data into multiple tables to reduce redundancy and prevent inconsistencies

Question 2

What is 1NF?

Answer 2

We need to eliminate repeating columns or groups of data. Break data into the smallest pieces you can and provide a column for each piece.

Question 3

What is 2NF?

Answer 3

Eliminate redundant data.

Question 4

What is 3NF

Answer 4

Eliminate columns not dependent on key filed

The data in a field is not determined by data in another field that is not part of the field e.g. calculations

Question 5

What are some of the things we can do to get out table into 1NF?

Answer 5

Add a unique identifier for each record in the table

Break down information into the smallest pieces you can e.g. name consists of forename and surname

Question 6

What’s the test for the third normal form?

Answer 6

Looking at a piece of data, does it uniquely identify the entity (apart from the key). The answer should be no.