HOWTO: Exclude domain class from database?




I have this project where I have the following domain class structure:

1. project.core -,, [implements IRequest], [implements IResponse]
2. project.entity - AccountProfile.groovy, Contribution.groovy, etc.
3. project.service - LoginService.groovy, ContributionService.groovy, etc.
4. - LoginRequest.groovy, LoginResponse.groovy, etc. (Note: all these classes are either Requests or Responses and they derive from either RequestBase or ResponseBase)

A short description: 'core' contains classes which carry core logic; 'entity' are things that should appear in the database. Package 'service' have the service classes which handle ORM while 'business' is more like a collection of View-Models.

My problem is simple: I want to make sure that NONE of the classes in packages 'core' and 'service' appear in the database. How do I do it?