Planning the Physical Model to Enforce Correctness

Translating the logical model to the physical model requires making several design decisions, especially as the app becomes more complex and needs to manage more types of data. This should be done in two discrete steps. The first is to plan exactly how we are going to store the data in the database. The next is how to write a Rails migration to implement this plan.

Whereas the logical model was for building alignment and discovering business rules, the physical model is for accurately managing data that conforms to those rules. This means that correctness, precision, and accuracy are paramount.

The design decisions we’ll make amount to how and where we will enforce the correctness of the data. Our database is an incredibly powerful tool to do this, and it’s where most of our constraints around correctness should go.