title: Bulk Update in Mongoose
body: <p>For eg, I have a set of document :</p>
  
  <pre><code>{ "_id" : ObjectId("5b7c1527c07abb08fc28febe"), "code" : "0001", "time" : ISODate("2014-07-04T09:15:00Z"), "open" : 0, "close" : 0, "high" : 0, "low" : 0, "volume" : 0, "bVolume" : 0, "sVolume" : 0 }
  { "_id" : ObjectId("5b7c1527c07abb08fc28febf"), "code" : "0001", "time" : ISODate("2014-07-04T09:16:00Z"), "open" : 0, "close" : 0, "high" : 0, "low" : 0, "volume" : 0, "bVolume" : 0, "sVolume" : 0 }
  { "_id" : ObjectId("5b7c1527c07abb08fc28fec0"), "code" : "0001", "time" : ISODate("2014-07-04T09:17:00Z"), "open" : 0, "close" : 0, "high" : 0, "low" : 0, "volume" : 0, "bVolume" : 0, "sVolume" : 0 }
  { "_id" : ObjectId("5b7c1527c07abb08fc28fec1"), "code" : "0001", "time" : ISODate("2014-07-04T09:18:00Z"), "open" : 0, "close" : 0, "high" : 0, "low" : 0, "volume" : 0, "bVolume" : 0, "sVolume" : 0 }
  { "_id" : ObjectId("5b7c1527c07abb08fc28fec2"), "code" : "0001", "time" : ISODate("2014-07-04T09:19:00Z"), "open" : 0, "close" : 0, "high" : 0, "low" : 0, "volume" : 0, "bVolume" : 0, "sVolume" : 0 }
  </code></pre>
  
  <p>I would like to retrieve and manipulate them then update them in mongodb. It is running extremely slow with saving each and everyone of them one by one with the function save() in mongoose. By any chance, one could save all of the array in a go? Please mind that each query return almost 300,000 documents. Suggesting a way to loop through them in nodejs without hitting stack overflow (The real stack overflow not the web site :P) would be handy. Thanks in advance.</p>