I have a collection for which we must minimise space in a MongoDB.
Some of the field for an entry are sometime null. In that case, I would like to field to be absent from the entry.
One solution I have is to first insert the entry for which every field is sure not to be null. This is doe with save property, using a structure.
The question is how to now add a field to an existing entry in the collection?
I save the datas in DB through C#.