title: Is interval call back unnecessary in multipage Dash App in Python?
body: <p>I am building a multi-page web application using Plotly-Dash in Python.
  One of the pages has an interval callback, which reloads data from an SQL server every one hour.
  It's occurred to me that maybe the interval callback is not necessary because the multi-page app calls each app when it's requested. 
  Does anyone know about it?
  Thanks!</p>