News for hackers. Stuff that matters.

A comment on MongoDB queries don’t always return all matching documents. Parent comment

Re:MongoDB queries don’t always return all matching documents by throwaway420 on Tuesday June 07, 2016 @06:24PM (#11858480)
Like with any online community, Hacker News can be kind of an echo chamber where groupthink reigns and alternative points of view aren't encouraged. MongoDB hype has died down here, but there are still some people that are fans.

There are some things MongoDB does fairly well:

* MongoDB is really easy to use

* Document databases can be great and flexible solutions for some kinds of projects

* Documentation is fairly good so learning the basics isn't too hard even if you know nothing about it

* scales fairly well at the initial stages

* arguably quicker to get a project off of the ground with than traditions RDBMs, which might be the most important consideration for any startup even if a complete rewrite would eventually need to take place

That being said, I've used MongoDB significantly before and it wouldn't be my first choice for most types of new project: PostgreSQL probably would be

[ Parent | on HN ]
Re:MongoDB queries don’t always return all matching documents by chaostheory on Tuesday June 07, 2016 @07:11PM (#11858788)
About the only thing I agree with is how great their docs are.

* Mongo is only easy to learn. Beyond simple demos, it gets harder and harder to use as projects evolve i.e. you have to do a lot of work yourself imo this is a common problem with nosql datastores that isn't exclusive to Mongo

* "Document databases can be great and flexible solutions for some kinds of projects": Postgresql has been able to work directly with JSON for some time now. There are also other document datastores that are more reliable than Mongo

* Scaling with Mongo is difficult, specifically the crazy setup. Even if you set it up properly, the results don't tend to match the marketing https://aphyr.com/posts/322-jepsen-mongodb-stale-reads

* "arguably quicker to get a project off of the ground with than traditions RDBMs" unless you're using Meteor, I'm also going to disagree here. Most frameworks target a relational database by default. Developing by convention tends to get you off the ground much faster than using something more specialized and niche

[ Parent | on HN ]
Re:MongoDB queries don’t always return all matching documents by rdtsc on Tuesday June 07, 2016 @08:28PM (#11859164)
But they do make great mugs. Who here doesn't have at least a couple of MongoDB mugs. I don't use MongoDB and still have a bunch from random conferences over the last 3-4 years.
[ Parent | on HN ]
Re:MongoDB queries don’t always return all matching documents by partycoder on Tuesday June 07, 2016 @07:09PM (#11858764)
https://xkcd.com/937/
[ Parent | on HN ]
Re:MongoDB queries don’t always return all matching documents by vonklaus on Tuesday June 07, 2016 @06:54PM (#11858664)
Idk about hype, but for node.js virtually every tutorial uses it. I think the stereotype is that postgres locks you into a data model but your needs vary drastically. I suspect mongo is harder to retool the schema than it is widely claimed, while pg/msql is slightly easier than is often claimed.

I doubt they meet in the middle, but both have great use cases. scaffolding out a quick isomorphic js app is great for mongodb for example. pg is faster and more robust.

its just tech, depends what you are optimizing for

[ Parent | on HN ]
Re:MongoDB queries don’t always return all matching documents by dcosson on Wednesday June 08, 2016 @12:22AM (#11860002)
> scales fairly well at the initial stages

Not sure what that means, but scalability is the worst thing about mongo (though my experience with mongo is all from ~2.5 ish years ago). As soon as your working set of indices gets bigger than memory, performance falls off a cliff and your entire app grinds to a halt. In my experience, mysql and postgres have a more gradual decline in performance so you have some time with only mildly degraded performance to figure out a solution (plus they have more options for tuning which can buy you more time).

[ Parent | on HN ]