-- Example: http://bl.ocks.org/andrewxhill/8306637

 WITH hgridA AS

  -- BIGS
  (SELECT CDB_HexagonGrid(ST_Expand(!bbox!, greatest(!pixel_width!,!pixel_height!) * 60),
    greatest(!pixel_width!,!pixel_height!) * 60) AS cell), bigs AS
      (SELECT * FROM
         (SELECT ST_Centroid(ST_Collect(i.the_geom_webmercator)) AS the_geom_webmercator,
            count(i.cartodb_id) AS points_count, 1 AS cartodb_id, array_agg(cartodb_id) AS id_list
          FROM hgridA, (SELECT * FROM stories_w_current --JS_PLACEHOLDER
             ) i
          WHERE ST_Intersects(i.the_geom_webmercator, hgridA.cell)
          GROUP BY hgridA.cell) t
       WHERE points_count > 200), hgridB AS

  -- MIDS
  (SELECT CDB_HexagonGrid(ST_Expand(!bbox!, greatest(!pixel_width!,!pixel_height!) * 50),
    greatest(!pixel_width!,!pixel_height!) * 50) AS cell), mids AS
  (SELECT * FROM
     (SELECT ST_Centroid(ST_Collect(i.the_geom_webmercator)) AS the_geom_webmercator,
        count(i.cartodb_id) AS points_count, 1 AS cartodb_id, array_agg(cartodb_id) AS id_list
      FROM hgridB, (SELECT * FROM stories_w_current --JS_PLACEHOLDER
         ) i
      WHERE ST_Intersects(i.the_geom_webmercator, hgridB.cell)
        AND cartodb_id NOT IN (SELECT unnest(id_list) FROM bigs)
      GROUP BY hgridB.cell) t
   WHERE points_count > 75), hgridC AS

   -- MIDSMALLS
  (SELECT CDB_HexagonGrid(ST_Expand(!bbox!, greatest(!pixel_width!,!pixel_height!) * 40),
    greatest(!pixel_width!,!pixel_height!) * 40) AS cell), midsmalls AS
  (SELECT * FROM
     (SELECT ST_Centroid(ST_Collect(i.the_geom_webmercator)) AS the_geom_webmercator,
        count(i.cartodb_id) AS points_count, 1 AS cartodb_id,
        array_agg(cartodb_id) AS id_list
      FROM hgridC, (SELECT * FROM stories_w_current --JS_PLACEHOLDER
         ) i
      WHERE ST_Intersects(i.the_geom_webmercator, hgridC.cell)
        AND cartodb_id NOT IN (SELECT unnest(id_list) FROM bigs)
        AND cartodb_id NOT IN (SELECT unnest(id_list) FROM mids)
      GROUP BY hgridC.cell) t
   WHERE points_count > 45),
    hgridD AS

  -- SMALL
  (SELECT CDB_HexagonGrid(ST_Expand(!bbox!, greatest(!pixel_width!,!pixel_height!) * 30),
    greatest(!pixel_width!,!pixel_height!) * 30) AS cell), smalls AS
  (SELECT * FROM
     (SELECT ST_Centroid(ST_Collect(i.the_geom_webmercator)) AS the_geom_webmercator,
        count(i.cartodb_id) AS points_count, 1 AS cartodb_id,
        array_agg(cartodb_id) AS id_list
      FROM hgridD, (SELECT * FROM stories_w_current --JS_PLACEHOLDER
         ) i
      WHERE ST_Intersects(i.the_geom_webmercator, hgridD.cell)
        AND cartodb_id NOT IN (SELECT unnest(id_list) FROM bigs)
        AND cartodb_id NOT IN (SELECT unnest(id_list) FROM mids)
        AND cartodb_id NOT IN (SELECT unnest(id_list) FROM midsmalls)
      GROUP BY hgridD.cell) t
   WHERE points_count > 25),

    hgridE AS

  -- SMALLEST
  (SELECT CDB_HexagonGrid(ST_Expand(!bbox!, greatest(!pixel_width!,!pixel_height!) * 20),
    greatest(!pixel_width!,!pixel_height!) * 20) AS cell), smallest AS
  (SELECT * FROM
     (SELECT ST_Centroid(ST_Collect(i.the_geom_webmercator)) AS the_geom_webmercator,
        count(i.cartodb_id) AS points_count, 1 AS cartodb_id,
        array_agg(cartodb_id) AS id_list
      FROM hgridE, (SELECT * FROM stories_w_current --JS_PLACEHOLDER
         ) i
      WHERE ST_Intersects(i.the_geom_webmercator, hgridE.cell)
        AND cartodb_id NOT IN (SELECT unnest(id_list) FROM bigs)
        AND cartodb_id NOT IN (SELECT unnest(id_list) FROM mids)
        AND cartodb_id NOT IN (SELECT unnest(id_list) FROM midsmalls)
        AND cartodb_id NOT IN (SELECT unnest(id_list) FROM smalls)
      GROUP BY hgridE.cell) t
   WHERE points_count > 1)

SELECT the_geom_webmercator, 1 points_count, cartodb_id, ARRAY[cartodb_id], 'origin' AS src
FROM stories_w_current
WHERE cartodb_id NOT IN
    (SELECT unnest(id_list)
     FROM bigs)
  AND cartodb_id NOT IN (SELECT unnest(id_list) FROM mids)
  AND cartodb_id NOT IN (SELECT unnest(id_list) FROM midsmalls)
  AND cartodb_id NOT IN (SELECT unnest(id_list) FROM smalls)
  AND cartodb_id NOT IN (SELECT unnest(id_list) FROM smallest)
UNION ALL
SELECT *, 'bigs' AS src FROM bigs
UNION ALL
SELECT *, 'mids' AS src FROM mids
UNION ALL
SELECT *, 'midsmalls' AS src FROM midsmalls
UNION ALL
SELECT *, 'smalls' AS src FROM smalls
UNION ALL
SELECT *, 'smallest' AS src FROM smallest