I have a CSV file that I need to save in mongo. My collection already have some data (couple millions) and I need to save into the database just the new ones and ignore the ones that were already in the collection.

How can i do that? I already have the code below:

Map<String, String> writeOverrides = new HashMap<String, String>(); 
writeOverrides.put("collection", this.collection);
writeOverrides.put("replaceDocument", "false");
writeOverrides.put("ordered", "false");
WriteConfig writeConfig = WriteConfig.create(getJavaSparkContext()).withOptions(writeOverrides);
MongoSpark.save(ds.write().mode(SaveMode.Ignore), writeConfig);

I've already tried all the SaveModes and none of them worked the way I need.

PS: I'm using only _id as index