> What are good schema examples? Anything that doesn't break the first normal form("1NF")[1]. > And what are some poor examples? Anything that breaks 1NF. Y

> What are good schema examples? Anything that doesn't break the first normal form("1NF")[1]. > And what are some poor examples? Anything that breaks 1NF. You break 1NF when... * a column cannot be described by the key, ex. user.id describes user.name but not user.items_purchased. * values in a column are repeated, ex. a user table that stores multiple addresses for the same user should be split into an addresses table. Treat tables as classes and you'll be fine. Just like a method may not belong in a class, a column may not belong in a table. [1](https://en.wikipedia.org/wiki/First_normal_form https://en.wikipedia.org/wiki/First_normal_form)