Unordered bulk update in MongoDB using JAVA

Question

I have MongoDB documents like:

{_id:1001, "title":"abc", "author":"xyz"}

What is the best way to update author for 1 million such documents? I came to know about the unordered bulk update in MongoDB. How to implement that using Mongo's Java Driver.

Answer 1

    MongoClient mongo = new MongoClient("localhost", 27017);
    DB db = (DB) mongo.getDB("test1");
    DBCollection collection = db.getCollection("collection");
    BulkWriteOperation builder = collection.initializeUnorderedBulkOperation();
    builder.find(new BasicDBObject("_id", 1001)).upsert()
                    .replaceOne(new BasicDBObject("_id", 1001).append("author", "newName"));
    //append all other documents 
    builder.execute();