def METHOD_NAME(ns):
    """Return a tuple of (db, collection) from the 'db.coll' string."""
    if ns:
        # NOTE[matt] ns is unicode or bytes depending on the client version
        # so force cast to unicode
        split = to_unicode(ns).split(".", 1)
        if len(split) == 1:
            raise Exception("namespace doesn't contain period: %s" % ns)
        return split
    return (None, None)