javascript - MongoDB: best way to update the field using the value of another field

Question

I have a code in NodeJS that updates the fields of a collection but it is very slow. My collection contains +16 million documents, do any of you know a better way to do this?

        const db = client.db("db");
        const collection = db.collection("collection");

        var cursor = product.find({});

        var manipulator = function(document) {
            document.fieldCopy = document.field;
            
            return { $set: document };
        };

        while (await cursor.hasNext()) {
            var thisdoc = await cursor.next();
            var newDoc = manipulator(thisdoc);
            product.updateOne({ "_id": thisdoc['_id'] }, newDoc);
        };

MongoDB version: 4.0.22

Sorry for the bad English!

Answer 1

等待大神答复