SQL LAST_VALUE

What & Why

LAST_VALUE(column) should return the final row's value in the window, repeated on every row — the mirror of FIRST_VALUE. In practice, it almost always needs one extra clause to actually behave that way.

See How It Works

SELECT
  date_day,
  dau,
  LAST_VALUE(dau) OVER (
    ORDER BY date_day
    ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
  ) AS latest_dau
FROM growth.daily_active_users
ORDER BY date_day;