Template
single collection
multiple collections
mgodatagen
update
indexe
explain
Stage
Database
bson
mgodatagen
[{"key":[{a:-23,b:"b"},{a:-34,b:"d"},{a:-15,b:"c"},{a:-51,b:"v"}]}]
Query
db.collection.aggregate([{$addFields:{winner:{$first:{$filter:{input:"$key",cond:{$eq:["$$this.a",{$max:"$key.a"}]}}}}}}])
Result