title: How to maintain chat data?
body: <p>I have a curious question...
  I wanted to know how to maintain chat data in a database.
  I have been using a php-mysql application, that stores chat data of users in a database.</p>
  
  <p>Now my question is that, if the chat data increases, say, to some millions of records, how to store it? Does mysql support it, or have any limitations or burden ?</p>
  
  <p>Take the example of gmail chat. I can chat unlimited and can also retrieve all my previous chat data. How is it possible ?</p>
  
  <p>Can anyone answer this typical question of myne ?</p>