PostgreSQL: generate a random series with configurable start, max and step.

postgresql-random-series.sql

with recursive t (n) as (
  with base as (
    with settings as (
      select
        10000 as max
        , array[1000,2000] as start_range
        , array[10,20] as step_range
    )
    select
      (random() * (start_range[2] - start_range[1]) + start_range[1])::int as start
      , step_range
      , max
    from settings
  )
  select start from base
  union all
  select n + (random() * (step_range[2] - step_range[1]) + step_range[1])::int
  from t cross join base
  where n < max
)
select n
from t;