Ask HN: Do you still use MongoDB? • Hacker News Board

Re: Ask HN: Do you still use MongoDB?

#81

Post by doublesCs » Fri, May 22, 2020, 2:14 PM UTC

scarface74 wrote: post #67

doublesCs wrote: post #58

Earlier quoted context omitted.

> much of the anti-mongo sentiment is around people who used it in 2009-ish. So? I think this is a very plausible way of measuring how much you should trust something. There had to be a downside to the "move fast and break things" that mongodb subscribes to (i.e., add features now, think about reliability later). As it turns out, they moved fast and broke their reputation.

You make technical decisions based on what happened a decade ago? Do you make all decisions based on ten year old information?

Depends on what.

You seem to think this is about tech. It's not. It's about company culture, trust, and reputation.

Code can change reasonably fast, in some cases 10 years is enough to replace an entire codebase. But company culture has or can have an expected life time way longer than 10 years. In this case, my heuristic is justified.

Re: Ask HN: Do you still use MongoDB?

#82

Post by smoe » Fri, May 22, 2020, 2:15 PM UTC

josephg wrote: post #27

No. Every time I've used mongodb we've ended up regretting it for one reason or another. And migrating to a different database after launch is a huge hassle. I've done a couple projects where we kicked off with postgres using JSONB columns for early iteration. Then we gradually migrated to normal SQL columns as the product matured and our design decisions crystallized. That gave us basically all the benefits of mongo…

I never understood the appeal of the JSON to SQL columns workflow.

At least with the ORM(-ish) tools I worked with, it always felt much more straightforward to just change classes within the application code and automatically generate the respective migrations files to be run on the relational database, than having to interact as a human with json (for the app as well as for business intelligence and reporting/monitoring).

I feel I have handwritten significantly more schema and data migration code for non-sql databases and JSONB in Postgres than for relational databases in the last 10 years.

Sure once the database growths bigger, those automatically generate migrations files don't work as seamlessly anymore and can be dangerous, but no tool or database magically solves all the problems at scale.

Re: Ask HN: Do you still use MongoDB?

#83

Post by scarface74 » Fri, May 22, 2020, 2:18 PM UTC

doublesCs wrote: post #81

scarface74 wrote: post #67

Earlier quoted context omitted.

You make technical decisions based on what happened a decade ago? Do you make all decisions based on ten year old information?

Depends on what. You seem to think this is about tech. It's not. It's about company culture, trust, and reputation. Code can change reasonably fast, in some cases 10 years is enough to replace an entire codebase. But company culture has or can have an expected life time way longer than 10 years. In this case, my heuristic is justified.

Are you not buying iPhones because Apple’s first music player had no wireless and less space than the Nomad?

(For the younger people https://slashdot.org/story/01/10/23/1816257/apple-releases-i...)

Re: Ask HN: Do you still use MongoDB?

#84

Post by UK-Al05 » Fri, May 22, 2020, 2:18 PM UTC

For those using postgres with jsonb, how easy it to scale postgres horizontally?

We have used SQL databases in the past, and we've had to vertically scale them with incredibly expensive hardware.

Re: Ask HN: Do you still use MongoDB?

#85

Post by Buttons840 » Fri, May 22, 2020, 2:19 PM UTC

Does MongoDB still use multi-maps? That is, can a map still have multiple of the same key? This led to a very tricky bug at my last place of work, where the MongoDB Ruby client would see different values than the Python client. It's not a problem with MongoDB, per se, but many of the clients assume Mongo stores maps, when it really stores multi-maps. And it did hurt my opinion of the database seeing that most of its users we're not actually aware of the data structure it was based on.

https://stackoverflow.com/a/35070928

Re: Ask HN: Do you still use MongoDB?

#86

Post by alkonaut » Fri, May 22, 2020, 2:24 PM UTC

Absolutely. Though by ”use” I mean maintain apps that wouldn’t be mongo today (and shouldn’t have been to begin with).

Not worth migrating off it for small internal apps though.

Re: Ask HN: Do you still use MongoDB?

#87

Post by stevievee » Fri, May 22, 2020, 2:26 PM UTC

Beefin wrote: post #22

Yes, use it with Atlas for every one of my companies' projects. - The document model is a no-brainer when working with JS on the front-end. I have JSON from the client, and Dictionaries on the backend (Flask), so it's as easy as dumping into the DB via the pymongo driver. No object relational mapping. - Can scale up/down physical hardware as needed so we only pay for what we use - Sharding is painfully easily, with o…

I've used mongo before and I just started using Atlas. Anything you don't like about it?

Re: Ask HN: Do you still use MongoDB?

#88

Post by mbell » Fri, May 22, 2020, 2:27 PM UTC

013a wrote: post #74

Yes. If we were going to start from scratch today, we'd probably use Postgres. But, realistically, the primary motivation behind that decision would be because Postgres is available on AWS, and that would centralize more of our operations. (DocumentDB is, of course available. Its not Mongo. I'd be curious to hear from people who actually had Mongo deployments and were able to move to DocumentDB; its missing so many o…

> We're not going to be migrating terabytes of data

You may have dramatically less 'real data' than mongo makes you think you do. I migrated one of our mid sized database out of mongo and into PG a couple years ago. The reduction in size was massive. One table in particular that was storing a small number of numeric fields per doc went from ~10GB to ~50MB. I wouldn't expect this with all datasets of course, but mongo's document + key storage overhead can be massive in some use cases.

Re: Ask HN: Do you still use MongoDB?

#89

Post by takeda » Fri, May 22, 2020, 2:28 PM UTC

heipei wrote: post #54

frankjr wrote: post #53

Yes. We have applications running on both PostgreSQL and MongoDB and I find that working with MongoDB is just more pleasant. I think it mostly boils down to my preference of document databases as opposed to relational ones. It feels much more natural to me to embed / nest certain properties within a document instead of spreading it across several tables and then joining everything together to get the complete data. M…

Yep, the update operators for MongoDB are really great and not replaceable with Postgres. Now if only MongoDB had a good sharding story it would be a worth contender for me.

As a person not familiar with mongo, what is it? From looking at the manual or looks like it's Mongo's equivalent of UPDATE statement.

Re: Ask HN: Do you still use MongoDB?

#90

Post by vivekkalyan » Fri, May 22, 2020, 2:28 PM UTC

Anyone has thoughts about cassandra and how it compares to mongodb? There seems to be a big enterprise push with azure's cosmosdb, but I've not heard much about it from people who have actually used it.