MongoDB Product MapReduce 3

gistfile1.js

map = function(){
	var size;
	for (size in this.sizes) {
	  emit(size, {size: this.sizes[size], price: this.sizes[size] * this.price });
	}
};

reduce = function reduce(key,values){

    var result = { sizeCount: 0, priceCount: 0 };

  	values.forEach(function(value){
  		result.sizeCount += value.size;
  		result.priceCount += value.price;
  	});
  	
    return result;
}
> db.product.mapReduce(map,reduce,{out:"productMapReduce3"})
{
	"result" : "productMapReduce3",
	"timeMillis" : 67,
	"counts" : {
		"input" : 6,
		"emit" : 18,
		"reduce" : 3,
		"output" : 3
	},
	"ok" : 1,
}
> db.productMapReduce3.find()
{ "_id" : "L", "value" : { "sizeCount" : 11, "priceCount" : 215 } }
{ "_id" : "XL", "value" : { "sizeCount" : 19, "priceCount" : 450 } }
{ "_id" : "XXL", "value" : { "sizeCount" : 24, "priceCount" : 580 } }