JonCrawford

class VisitorStats
  def initialize
    @redis = Redis.new
  end

  # every time there's a hit, increment a counter for the
  # day and week, and add the session id to a set of unique
  # vistitors for the day/week
  def hit(session_id)
    today = Date.today

hsurreal

with
    dau as (
        -- This part of the query can be pretty much anything.
        -- The only requirement is that it have three columns:
        --   dt, user_id, inc_amt
        -- Where dt is a date and user_id is some unique identifier for a user.
        -- Each dt-user_id pair should be unique in this table.
        -- inc_amt represents the amount of value that this user created on dt.
        -- The most common case is
        --   inc_amt = incremental revenue from the user on dt