In this lesson, we’ll learn how to design TypeDB schemas using the conceptual PERA data model. We’ll start with an overview of the PERA model and see how it is implemented by TypeDB and TypeQL. We’ll then work through the design of a small part of the bookstore schema and cover major design decisions like choosing object types, using type hierarchies, and using interface hierarchies. We’ll also see how we can avoid some specific problems like data redundancies, inheritance overuse, and interface redundancies.