Is it possible to limit the results of group function? I have a huge dataset and I want to group the results by an id and for each id to create an array with coordinates.

The output result is:

{u'_id': u'229136000', u'COORDINATES': [[160.6752, -27.80978]]} \{u'_id': u'567014500', u'COORDINATES': [[128.1873, -3.672835], [128.1876, -3.673245]]}
...

As I see the code groups all the id's in dataset and the performance is very bad.

Code:

getPositionsOfshipsgrouped = db.collection.aggregate([ { "$group" :
{"_id" :
  "$properties.MMSI",
  "total": {"$sum": 1},
  "COORDINATES": { "$push": "$geometry.coordinates"} }},
{"$match": {"total":{"$gte": 0}}} ])

If I add $limit in the end of this query, the group function executed and then the limit so there is no change in performance.

Is it possible to limit the results of a group function?