select
  o.user_id as user_id,
  o.id as order_id,
  p.id as post_id,
  o.timestamp as order_time,
  p.timestamp as post_view_time
from "orders.csv" o 
asof join "post_views.csv" p
on o.user_id = p.user_id
and o.timestamp >= p.timestamp
order by order_time desc;