SEGW : Copy Project vs Redefine(OData Service)

Question

Dear Friends,
This is regarding the differences between various modeling approaches in SEGW
1. An Existing Project ( and Technical Service , say, Parent 1.0 ) is live
2. A new Project ( and Technical Service , say, Child 1.0) is to be implemented.
What is the real difference between
(A) ... copying the existing project "Parent" to  "Child" and publishing the Technical service as "Child 1.0"
(B) ...copying the existing project "Parent" to  "Child" and publishing the Technical service as "Parent 2.0"
(C) ...Redefining the "Parent 1.0" in a new project "Child" and "Overwrite Base/Extend the Service" ...which publishes the Technical Service as "Parent 1.0"
(D) ...Redefining the "Parent 1.0" in a new project "Child" ..without "Overwrite Base/Extend the Service" .. and publish the Technical Service as "Child 1.0"
In other words, what really is the idea of "Redefine >OData Service (GW)" ...( with / without "Overwrite Base/Extend the Service" )
Many thanks for your patience
Suresh

Answer 1

Hi Suresh,
by copying the project you create a complete independent new project, which does not have any relation to the original project. The runtime objects (model provider classes and data provider classes) are independent from those of the first project.
By redefining the project you can select which entities and which associations you want to use in your child project. Those redefined objects can't be changed in the child project, you only can redefine names and labels. On the other hand if you change any of the redefined object attributes in the parent project the changes will also be available in the child project.
And the data provider class of the child project inherits from the one of the parent project.
So you have a real parent-child relationship.
Redefining with option "Extend" means to add objects of the parent project, which haven't been redefined before.
Redefining with option "Overwrite" means to redo the redefinition. All redefinitions done earlier will be overwritten. Objects which had been redefined before, but are not selected in the new redefinition will be deleted from the child project.
Hope that makes it a little bit clearer.
Regards,
Juergen