Am I Properly Normalizing this Data

Question

I am completing normalization exercises from the web to test my abilities to normalize data. This particular problem was found at: https://cs.senecac.on.ca/~dbs201/pages/Normali

Answer 1

In a first step you could create the following tables (assuming pet_id is unique in the table):

Pets:   pet_id, pet_name, pet_type, pet_age, owner
Visits: pet_id, visit_date, procedure

Going further you could split procedure since the description is repeating:

Pets:       pet_id, pet_name, pet_type, pet_age, owner
Visits:     pet_id, visit_date, procedure_id
Procedures: procedure_id, description

Although there can be multiple procedures on the same visit_date for the same pet_id, I see no reason to split those further: a date could (in theory) be stored in 2 bytes, and splitting that data would create more overhead (plus an extra index).

You would also want to change pet_age to pet_birth_date since the age changes over time.

Since this is the first exercise in your list, the above will probably be more than enough.

Going even further:

An owner can have multiple pets, so another table could be created:

Pet_owners: owner_id, owner_name

and then only use owner_id in the Pets table. In a real system there would be customer_id, name, address, phone, email, etc. - so that should always be in a separate table.

You could even do the same for pet_type and store the id in 1 or 2 bytes, but it all depends on the type of queries you want to do later on the data.