Currently pxdb seems to treat relationships as one-way.
So if I have people and organztion objects, the
relationship between them (membership) is either people
associated with an organization or organization(s)
associated with a person. There doesn't seem to be a
way to have the relationships work both ways, so that I
can add an organization to a person object or a person
object to an organization and be able to remove the
information from both as well.