cohort

with reg as (
    select userid, date(eventtime) as reg_dt
    from "public"."table1"
    where eventname = 'registration'
),
visits as (
    select reg_dt, date(t1.eventtime) as visit_dt, count(distinct t1.userid) as visit_cnt
    from "public"."table1" t1
    join reg
    on t1.userid = reg.userid and date(t1.eventtime) > reg.reg_dt
    where eventname = 'visit'
    group by reg_dt, date(t1.eventtime)
),
dd as (
select
  '2022-01-10'::DATE + SEQUENCE.number as dt
from
  GENERATE_SERIES(0, 333) as SEQUENCE (number)
)
select r.reg_dt, dd.dt as visit_dt, r.reg_cnt, coalesce(v.visit_cnt, 0) as visit_cnt,
       1.0*coalesce(v.visit_cnt, 0)/r.reg_cnt as share
from
    (
       select reg_dt, count(distinct userid) as reg_cnt
       from reg
       group by reg_dt
    ) r

join dd
on dd.dt > r.reg_dt

left join visits v
on r.reg_dt = v.reg_dt and dd.dt = v.visit_dt