title: Saving chat transcripts in nosql databases
body: <p>I'm building a chat server app using node.js.</p>
  
  <p>I need to save chat transcripts on the database and would like
  to play with nosql database like mongodb. If i was in relational db world, i would
  create users, chat_sessions and chat_messages tables and, for every new message, i'd
  append new record in chat_messages table.</p>
  
  <p>Which is the best approach in nosql? </p>
  
  <p>Do i have to create a chat_session document and, inside of it, create 
  a chat_messages structure that is updated for every new message or
  is there a better way to do it for nosql/mongodb?</p>