I have a situation where I need to issue a `commit()` without expiring the
object/attributes from the session. I'm in a `Celery` task, and need to
log progress at certain points into a status column. the status points
will be used to troubleshoot and fix jobs that didn't correctly complete.
you can make a new Session() with expire_on_commit=False, that can be
from your sessionmaker. the settings you apply there override whats in
the original factory.
Though for status logging I tend to just use a separate
Session/transaction for that, that way the main transaction can maintain
