Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
I’m using MongoDB with Node.js. Is there any speed advantage to using a MapReduce in Mongo as opposed to getting the full result set and doing a map and reduce in JS on my own?
There is usually no performance advantage to retrieving the entire resultset and performing the m/r app-side. In fact, in almost all situations cramming the entire resultset in memory on your node server is a particularly bad idea.
Doing the map/reduce on MongoDB will make sure no bandwidth between the database and your app server is wasted on retrieving the resultset and writing back the results of your m/r. MongoDB’s map/reduce can also be easily scaled up.
TL;DR : Always do it in MongoDB