title: Mongo error when using aggregation: sort exceeded memory limit
body: <p>I get the mongo error <code>exceeded memory limit</code> with error code <code>16819</code> when I use aggregation sort.</p>
  
  <p>Im using mongo 2.6.</p>
  
  <p>The query is as follows:</p>
  
  <pre><code>db.BASE_TABLE_CREATION_ExecuteHiveScript_26_V0.aggregate([
       { "$project" : { "visitor_localdate" : 1 , "_id" : 0}}, 
       { "$sort" : { "visitor_localdate" : -1}}
  ])
  </code></pre>