"There's no difference between this and designing the classes first." Databases are designed to be shared structures accessible from many applications, so it's

"There's no difference between this and designing the classes first." Databases are designed to be shared structures accessible from many applications, so it's not a 100% direct comparison. When focusing on a single process of a single application, of course that leads to some simplifications (no IPC, all datatypes match up perfectly, no concurrency problems). "you're not constrained by relational requirements" I don't see relational as more constrained or less constrained than OO. It's different. For instance, in OOP I often feel like it's forcing a hierarchical structure upon the design. Inheritance feels very constraining to me in comparison to the free joining of one table to another based on the values inside (not necessarily based on explicit connections in the design).