Hi!
Hope you can help my with you issue...
I made a domain model (http://cedev.com.ar/model.jpg) and what I'm trying to is the NHibernate mappings to persist it. (It's uses the Decorator Pattern, of course..)
It's importante to know that a Person might be a Student and a Tutor at the same time (that's why it's not a simple inheritance)
I created a table for ConcretePerson, another one for SystemUser (only with the Id), other for Tutor and other for Student (only with the Id too). The problem is that a partner is criticizing me (and with good reasons) that the ConcretePerson table should have fields like "IsStudent", "IsTutor" and so on, to improve the performance and don't let NH make a lot of joins to find a student...

What can I do??

Thanks in Advance!,
Diego