gistfile1.txt

WITH clusters AS (
SELECT
 ST_Collect(the_geom_webmercator) as g,
 count(*) as count
FROM the_tornados WHERE the_geom_webmercator && !bbox!
GROUP BY ST_SnapToGrid(the_geom_webmercator, greatest(!pixel_width!,!pixel_height!)*48)
)
SELECT row_number() over () as cartodb_id,
 count,
 least(100, greatest(count,10)) as size,
 ST_Centroid(g) as the_geom_webmercator
 from clusters