I agree with the school of "the right logic in the right layer". One definition of what make the right placing is also what is shared by what i.e. if a database is shared by two systems then I would expect all the logic that needs to be shared across those systems to either be data logic so sit in the RDBMS or operational logic that MAY sit in the middle application tier as reusable components.

Of course logic might be data driven and itself stored as data e.g. routing logic.