MongoDB function to create 100 000 documents

mongo-function.js

db.system.js.save({
        _id: "test",
        value: function () {
            var start = new Date();
            for (var i = 1; i <= 100000; i++) {
                db.getCollection('log').insert({
                    "key": (new ObjectId()).toString(),
                    "data": "some random data: " + (new ObjectId()).toString(),
                    "updated_date": new Date()
                })
            }
            return new Date() - start;
        }
    });