gistfile1.sql

with stddeviation as (
  select stddev(extract (epoch from coalesce(deactivated_at, now()) - created_at)) as s from users where type = 'ServiceUser'
),
average as (
  select avg(extract (epoch from coalesce(deactivated_at, now()) - created_at)) as a from users where type = 'ServiceUser'
)
select avg(coalesce(deactivated_at, now()) - created_at) as average
from users, average, stddeviation
where type = 'ServiceUser'
and extract(epoch from coalesce(deactivated_at, now()) - created_at) < average.a + (stddeviation.s * 2)
and extract(epoch from coalesce(deactivated_at, now()) - created_at) > average.a - (stddeviation.s * 2)