Data that was written to your production LUN is not discarded when you stop the session, it's the changes that were made to the production LUN during the session are discarded. Meaning you if you did an application upgrade and all went smooth, you are happy how it performs and have no intention to reverse the changes, you go ahead and stop the session.
Hello,  Reading the documentation I cannot really tell what is happening to the copy-on-write data when stopping a SnapView session.  Is this data lost or is it merged to the source LUN?  Thanks for your help in clearing this out.
Stopping a SnapView sesion