I'm woundering if it's possible to disable the intialization of JPA Stack competelly.

I some situation my application is executed in enviroment where database is not accessible. Application can survive this on application level. 
But technically i get some exception on intialization of Data Source. 

1) there musst be some way to disable JPA intialization at all (not needed withoud db. By profile or someting like that.
2) Or maby at least i can say Connection pool to not connect or somethinglike this. 
3) Other ideas?