Is the database a processing engine or a persistence layer? In this presentation we'll first go through a bit of history demonstrating how the database has been used in the past 30 years: at times it was a processing engine, and at other times it was just a persistence layer. Having witnessed many application development projects, we are convinced that the database ought to be used as a processing engine. The persistence layer approach, where all business logic is implemented outside the database has serious drawbacks in the areas of initial application development, ongoing maintenance, and most notably in the area of performance and scalability. We'll discuss these drawbacks, in particular the last one: we'll debunk once and for all that moving business logic out of the database benefits performance and scalability.