If you are referring to object-oriented polymorphism, "Out of the Tarpit" comments directly on this AT http://shaffner.us/cs/papers/tarpit.pdf page 12, the conclusion being that OO suffers from unnecessary state complexity.
In addition, the glut of ORMs demonstrate the various approaches to solving the impedance mismatch between the relational algebra and object-oriented architecture with no clear winning strategy.
Instead, the proposal from the "Out of the Tarpit" paper is "functional relational programming" which fuses relational algebra operations and declarative functional programming.
Primarily just that Java (7's) type system is categorically incapable of expressing more sophisticated types. You can get some basic type testing using abstract classes to define dataset column types. Java 8's type system might have some extra features to allow it to do this without significant boilerplate. E.g. To keep runtime generics in Java you can instantiate subclass instances which don't have type erasure.
The references solidsnack9000 mentions seem to be promising. I'll have to look into it! It seems like it'd apply to a system of using actors and data modeling I'm working on currently... Intriguing at least.
https://github.com/agentm/project-m36