This paper is actually interesting and talks about real-world schemas. I particularly like the concept of distinguishable nulls that define a sane equality operator, unlike the traditional SQL NULL.
The paper I was referring to used the category Poly, and literally just stated that Poly could be used for database migrations without elaborating further.
The paper I was referring to used the category Poly, and literally just stated that Poly could be used for database migrations without elaborating further.