OGM-233 OGM is not polymorphic 

https://hibernate.onjira.com/browse/OGM-233

This should fix the polymorphism problem.
The discriminator column it's created only if it's needed.As discussed with Emmanuel, at the moment the only supported strategy for the inheritance is the single table one.

Discriminator formulas are not supported, should we have to open an issue for that (I haven't found one)?

I  don't know how to check  if the discriminator column has been created, any suggestion?