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The Great Migration from MongoDB to PostgreSQL

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Re: The Great Migration from MongoDB to PostgreSQL

#91
post #11

Earlier quoted context omitted.

Their "Comprehensive Losses" for the last 3 years are (in thousands) (171,150) (343,375) (309,090) So there you go...

they lost 300 million in one year?

Stock compensation cash flow was positive meaning they added cash to their account.

Re: The Great Migration from MongoDB to PostgreSQL

#92
post #4

Earlier quoted context omitted.

They grew 30% if you look at revenue, but that's not how people determine whether a business is healthy. EBITDA is a better metric, and that number was getting dramatically worse every year until 2023. But even in 2023, EBITDA was -$202M. I don't see it ever approaching $0. So it's still a shit business on top of a shit product that no one ever really needed.

Why do you choose EBITDA? Last I heard it was utter nonsense”, at least according to Warren Buffet. https://m.youtube.com/watch?v=tvnKylAyLbQ

Buffett's criticism is that EBITDA is just accounting and he cares about cash flow, specifically also after paying for CAPEX (which is Investing Cash Flow so comes after Operating Cash Flow)

EBITDA is used in the industry because it is a proxy for operating cash flow. Sometimes you don't have all the available data needed to get to OCF, or you're looking at company guidance (for future EBITDA values) or analyst estimates. It's easier to keep the conversation at the EBITDA level because it requires fewer assumptions. Generally the revenue line is ~easy to estimate because you can conceptualize how to go from the current number of customers to some future number of customers, how many dollars per customers and so on and so forth.

Then as you work your way to EBIT (Operating Income) you still have to assume some gross margin, R&D expense, etc. These are pretty tangible. It should be pretty easy to get to estimated EBIT from what the company discloses in guidance or what analysts forecast. Since D&A is pretty linear over time, people generally assume it just remains constant as a % of revenue, so now you have EBITDA which is very much like cash flow

EBITDA is similar to cash flow because it adds back to EBIT the non-cash expense that is D&A. The reason it's good to look at it before interest and taxes is because you're also thinking about how much cash the whole enterprise generates, not how much cash goes to equity holders at the end (which is often called "Free" Cash Flow because it's not tied up with commitments to others)

Coming back to Buffett, in the industries he tends to pick stocks from, CAPEX is a major thing. Companies need to build factories, buy equipment, etc. So if you just look at future EBITDA without accounting for future CAPEX needs, you're fooling yourself.

Truth be told, in those industries everyone also looks at "EBITDA minus Capex". Maybe they do so now that he's bemoaned everyone for not doing it in the first place, but IMHO his criticism largely doesn't apply among valuation professionals. Maybe it does for stock traders, but not for valuation purposes like in an M&A context

Re: The Great Migration from MongoDB to PostgreSQL

#94

Ah, the old "I used a wrong product for my problem and now I complain the product is bad because it does not suit my case." defence. MongoDB is a document database. It is not supposed to be good at relations. Also lacking support with cloud providers and lacking experience with MongoDB is not MongoDB's problem, it is your poor decisionmaking. If you value those things, you should have taken it into account when you w…

Author of the article here!

The article itself does not "complain the product is bad" but some other comments in this thread would certainly suggest so. Instead, the article says that the use-case evolved, states reasons for why MongoDB was no longer suitable (while at some point it was) and why PostgreSQL was chosen instead, and discusses the migration process involved in the transition and the results.

Regarding lacking support with cloud providers and lacking experience with MongoDB is indeed NOT MongoDB's problem. However, it is a problem for users of the platform that are trying to self-host it with MongoDB as a database dependency and therefore justifies the PostgreSQL migration with PostgreSQL being a better candidate for this use-case.

To be clear, the article is not saying that MongoDB is bad and no fingers are being pointed. I would in fact say that there are an array of use-cases where MongoDB is an excellent choice (e.g. I resonate with the point on rapid prototyping).

Please don't skew the words.

Re: The Great Migration from MongoDB to PostgreSQL

#95

Earlier quoted context omitted.

It drives me batty to see people store 100MB JSON objects with a predictable internal structure as single records in an RDB rather than destructuring it and storing the fields as a single record. Like, yes, you can design it the worst possible way like that, but why? But I see it all the time .

Because schemas. The whole point of nosql is that you can alter your data model without having to reload the whole database

Actually, that's the whole point of RDBs: that you can alter your data model (in most cases) just by a simple DDL+DML query. And it is with NoSQL that you have to manually download all the affected data from the DB, run the transformation with consistency checks, and upload it back. Or, alternatively, you have to write your business logic so that it can work with/transform on-demand all the different versions of data objects, which to my taste is even more of a nightmarish scenario.

Re: The Great Migration from MongoDB to PostgreSQL

#96

The irony of it all is that MongoDB actually matured and you do not have to jump through hoops to have, say, transactions. I am ALL for Postgres, I even wrote a post about the importance of being fluent in relational databases: https://renegadeotter.com/2023/11/12/your-database-skills-ar... What grinds my gears is the whiplash caused by this frantic stampede from one hype to the next. I am just waiting for the AI hyp…

> The irony of it all is that MongoDB actually matured and you do not have to jump through hoops to have, say, transactions.

Are transactions still limited to a single document in Mongo?

Re: The Great Migration from MongoDB to PostgreSQL

#97

I use MySQL for everything - always have. Can someone hit me with a few reasons why you would use Postgres over MySQL? I don’t have any familial affinity to any database, but I’m not sure what the benefits to Postgres are relative to MySQL.

Architecture-wise, Postgres is more extensible. Another reason is licensing. Both contribute to a viral ecosystem.

https://www.bytebase.com/blog/postgres-vs-mysql/

Re: The Great Migration from MongoDB to PostgreSQL

#98
post #86
post #45

I have done this migration twice and rethinkdb to PostgreSQL once. At this point I think document DBs are as good as dead for new projects. They will live for a really long time still but are in contraction and rent seeking mode now. Expect MongoDB licensing and hosting to increase in price and languish in terms of feature development from here on out.

mongodb is a fortune 100 company and blows through expectations every quarter. doc dbs are far from dead.

I didn't say it wouldn't make a ton of money, there is a huge number of MongoDB instances out there in the wild in Fortune 500 due to the MEAN stack days (just like RoR before it). I fully expect the company to keep blowing away expectations by increasing how much revenue they extract from that existing customer base. That said they -still- aren't profitable, they might be profitable next quarter in fact I expect them to be with the current environment but to only reach profitability now after their glory growth days are behind them seems... well pretty garbage. If anything it reminds of me of GoPro except instead of cheap Chinese clones it's PostgreSQL and JSONB that is coming for their lunch.

Re: The Great Migration from MongoDB to PostgreSQL

#99
post #50

Earlier quoted context omitted.

I am not calling Postgres hype - it should have never been NOT hype. It's a reasonable default for most problems, Now all I read about is how Postgres is awesome, as if it's this great new thing. I guess that makes sense, as the new generation of engineers is rediscovering stable, reliable, lean technologies after a decade of excesses with "exotic" tech. For grey beards, it's all very odd. Like, "where have you all b…

I remember Robert C. Martin ("Uncle Bob") going on about how No-SQL will replace literally all SQL and that there is literally not a single use case for relational data and SQL. I wonder if he ever came back on that. Now, my opinion of Martin in general is not especially high and he's a bit of a controversial figure, but it wasn't just the kids. And Martin is also all about reliable software, so that makes it even mo…

I also remember Michael Stonebraker basically saying something, but being ignored...Along the lines of "I will see you all map reduce and nosql people in 20 years, after you have all reinvented SQL...."

Not an actual quote but a factual statement

Re: The Great Migration from MongoDB to PostgreSQL

#100
post #83

Some years ago we had so much problems with MongoDB that we also ditched it for Postgres. Never been happier. Not the reason, but very annoying: Why doesn't (perhaps this has changed?) MongoDB use SQL but Javascript with endless $s? It was always a pain writing ad-hoc queries.

> Why doesn't MongoDB use SQL Perhaps not the right answer, but SQL literally stands for Structured Query Language. I suppose you'd need an USQL?

Google says:

'The original full name of SQL was SEQUEL, which stood for "Structured English Query Language". A language which has been structured in English or lets say English-Like Query language which follows the syntax structure of English.'

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