json mongodb

mongoexport without _id field

I am using mongoexport to export some data into .json formatted file, however the document has a large size overhead introduced by _id:IDVALUE tuples.

I found a similar post Is there a way to retrieve data from MongoDB without the _id field? on how to omit the _id field when retrieving data from mongo, but not exporting. It is suggested to use: .Exclude("_id"). I tried to reqrite the –query parameter of mongoexport to somehow include the .Exclude("_id") parameter, but all of the attempts failed so far.

Please suggest what is the proper way of doing this, or should I revert to using some post-export techniques?