postgresql histogram

histogram.sql

--- credit: https://tapoueh.org/blog/2014/02/postgresql-aggregates-and-histograms/

with drb_stats as (
    select min(drb) as min,
           max(drb) as max
      from team_stats
),
     histogram as (
   select width_bucket(drb, min, max, 9) as bucket,
          int4range(min(drb), max(drb), '[]') as range,
          count(*) as freq
     from team_stats, drb_stats
 group by bucket
 order by bucket
)
 select bucket, range, freq,
        repeat('■',
               (   freq::float
                 / max(freq) over()
                 * 30
               )::int
        ) as bar
   from histogram;