I have a MongoDB Collection called Questions which holds JSON Objects that look like this:
"_id" : "49902cde5162504500b45c2c",
"question" : "Who are you?",
"category" : "Personal"
An alternate approach is to:
Set Last Processed Id = 0
Select from questions where id > [last processed id] order by id limit 1000
This will be more efficient than selecting everything and skip()'ing past the result set.
Alternatively add a 'processed' flag to your records so you can tell apart which records need processing and then query where processed = 0.