Template
single collection
multiple collections
mgodatagen
update
indexe
explain
Stage
Database
bson
mgodatagen
[{"likes":[1,2,3]},{"likes":[4,5]},{"likes":[6,7,8,9]}]
Query
db.collection.aggregate([{$set:{size:{$size:"$likes"}}},{$sort:{size:-1}}])
Result