Template
single collection
multiple collections
mgodatagen
update
indexe
explain
Stage
Database
bson
mgodatagen
[{userId:1,stats:{votes:[0,4,1,0,2]}},{userId:2,stats:{votes:[0,2,2,0,1]}}]
Query
db.collection.aggregate([{$group:{_id:null,totalSum:{$sum:{$sum:"$stats.votes"}}}}])
Result