I want to give users the possibility to dynamically add new columns at the runtime. I am using the Entity framework v1 ...
I did manage to read as xml and then change ss
Changing the Entity Model CSDL/SSDL will not change the types, because they are used to generate the types at design time. I don't think there is any practical way to modify those types at runtime to reflect your changes to the model.
In v1, you would need to generate a new assembly. This would also require redistributing EdmGen. I don't know if that's legal.
In EF v4, you could probably combine C# dynamic types with code-only modeling and come up with a pretty slick solution to your problem.