title: store the temporary data in memory array or database
body: <p>Just wonder if I need to store the temporary data in memory array or database(nosql)?</p>
  
  <p>Is there any performance difference?</p>
  
  <p>Somebody said nodejs is very dangerous to cache data in memory, it may lead to memory leak. And it cannot afford big data.</p>
  
  <p>Your comment welcome</p>