'Return all the ratios.
Or, if a ``min_start`` query param is present, return the (potentially
limited) ratios later than or equal to that. ``min_start`` should be
something like ``2001-07-30``.
If, somehow, half a ratio is missing, that ratio is not returned.'

def get_objects(self, request):

    min_start = request.GET.get('min_start')
    if min_start:
        try:
            _parse_date(min_start)
        except (ValueError, TypeError):
            min_start = None
    cursor = _cursor()
    query = ('\n                                                SELECT    n.start,    n.value,    d.value\n                                                FROM    kpi_metric    n\n                                                INNER    JOIN    kpi_metric    d    ON    n.start=d.start\n                                                WHERE    n.kind_id=(SELECT    id    FROM    kpi_metrickind    WHERE    code=%s)\n                                                AND    d.kind_id=(SELECT    id    FROM    kpi_metrickind    WHERE    code=%s)\n                                                ' + ('AND    n.start>=%s' if min_start else ''))
    args = [self.clicks_kind, self.searches_kind]
    if min_start:
        args.append(min_start)
    cursor.execute(query, args)
    return [dict(start=s, clicks=n, searches=d) for (s, n, d) in reversed(cursor.fetchall())]
