title: MongoDB: moving whole database to RAM dynamically
body: <p>I have a simple Node.js web application uinsg MongoDB on the backend. The way I set it up was to give each user his own database in MongoDB, since the users were not interacting, this was an easy way to ensure separate data by user.</p>
  
  <p>I was reading a book on MongoDB and there was a suggestion of moving as much of the database into RAM as possible to increase speed of reads/writes.</p>
  
  <p>This got me thinking, since for my app each user has his own database, and the database will surely be less than 1 gig in size (for the sake of this question, let's assume it's just a couple megs),  is there a way to quickly move the entire MongoDB database to RAM once the the user logs in?</p>