title: Creating file in GridFs (MongoDb)
body: <p>I have two collections, LogData and OptData. LogData is having just 600 records whereas OptData is having around 3 million records. To make some logical data, I am trying to merge both colletions. But merging simply by using mongo command create a document larger in size than 16 MB. </p>
  
  <p>Can I merge files using GridFs?</p>
  
  <p>My collections are like </p>
  
  <pre><code>   LogData
   [{
    "SId": 10,
     "NoOfDaya" : 9
    }
   {
   "SId": 11,
  "NoOfDaya" : 8
  }]
  
  
  
   OptData 
   [ {
       "SId": 10,
      "CId": 12
      }
  
  {
  "SId": 10,
   "CId": 13
     }]
  </code></pre>
  
  <p>I want something like </p>
  
  <pre><code>LogData
  [{
    "SId": 10,
     "NoOfDaya" : 9
     "OptData" : [{
        "CId": 12
      },{
      "CId": 13
     }
     ]
    }
    {
        "SId": 11,
       "NoOfDaya" : 8,
       "OptData" : []
   }]
  </code></pre>
  
  <p>I am able to do this by using mongodb find command but it create document size larger than 16 mb.Is it possible to do this using mongodb GridFS?</p>