berkum wrote:
Christian, unfortunately I need 99% portability if I am to switch to jpa.
You won't ever get that for any specification in the world.
I think you misunderstand the purpose of standardization. The goal is never a 100% guarantee that you can switch one product for another without touching any code. The goal is that you can switch if you have to, and that you can calculate the cost before you make that decision. If that decision is negative for a particular project, so be it.
I currently work on a real project and I use JPA only for half of my data access code, the rest is extremely sophisticated Hibernate stuff. And this is of course all just fine because the next person looking at it won't have any problems understanding the JPA part. Better 50% than nothing. If you really have architects or project managers who think otherwise, fire them before they do more damage.