> The meaning of "joins don't scale" is that they don't scale across database servers, when your dataset is too big to fit in a single database instance. Joins

> The meaning of "joins don't scale" is that they don't scale across database servers, when your dataset is too big to fit in a single database instance. Joins scale across rows, they don't scale across servers. But people have been saying "joins don't scale" for a lot longer than there have been companies that have today's giant's horizontal infrastructure. It's just been a sort of hipster anti-hipster anti-correctness brag since at least 1996, when I first heard it.