title: Mongodb C# GeoNEar is slow
body: <p>I've added a GeoNear Function with Mongodb C# like that:</p>
  
  <pre><code>` var options = GeoNearOptions.SetMaxDistance(rangeInKm / earthRadius /* to radians */)
                                                      .SetSpherical(true).SetDistanceMultiplier(6378.137);
                      collection.EnsureIndex(IndexKeys.GeoSpatial("PlacePoint"));'
  
  
   MongoDB.Driver.GeoNearResult&lt;MongoPlace&gt; Georesults = collection.GeoNear(Query.Null, coordinates[0], coordinates[1], TakeNum,options);
  </code></pre>
  
  <p>I have over 3000 places in the data... it's taking too long.
  how can I make it better</p>