'Sync all cached fields on demand.
Caution: this operation may be slower.'

def sync_all(self):

    update_key = ('set__%s' % self.name)
    for doc in self.document_type.objects:
        filter_kwargs = {}
        filter_kwargs[self.name] = doc
        update_kwargs = {}
        update_kwargs[update_key] = doc
        self.owner_document.objects(**filter_kwargs).update(**update_kwargs)
