MongoDB finding an item in an array and how to index properly -


i have documents stored so:

{     ...     "users" : [          {             "id" : "123456",             "username" : "john",             "address" : "fake st",         }     ], ... }

what best way of being able retrieve documents username "john". also, proper ways of indexing performance considering inside array. want index "users", or there better way? inside database 50+ million documents.

to find documents contain @ least 1 "john" in users array, use db.collection.find({"users.username":"john"});

to make faster, create index db.collection.createindex({"users.username":1});. indexes in mongodb can reach inside arrays , index individual array entries (this called multikey index).


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