Comment 1 for bug 1700660

There seem to be three solutions to this problem:

* Set the share_server model to be loaded immediately with share instances
* Set expire_on_commit to True in the sessionmaker
* Explicitly expire the session once the values have been captured from the database

Also, this goes without saying that drivers don't need to be handed sqlalchemy objects because they
don't need to perform any further database operations by themselves.