Just have to use locks to be careful with writes.
I figured I'd migrate it to a database after maybe 10k users or so.
One would think that for a startup of sorts, where things changes fast and are unpredictable, NoSQL is the correct answer. And when things are stable and the shape of entities are known, going for SQL becomes a natural path.
There is also cases for having both, and there is cases for graph-oriented databases or even columnar-oriented ones such as duckdb.
Seems to me, with my very limited experience of course, everything leads to same boring fundamental issue: Rarely the issue lays on infrastructure, and is mostly bad design decisions and poor domain knowledge. Realistic, how many times the bottleneck is indeed the type of database versus the quality of the code and the imlementation of the system design?
NoSQL gains you no speed at all in redesigning your system. Instead, you trade a few hard to do tasks in data migration into an unsurmountable mess of data inconsistency bugs that you'll never actually get into the end of.
> is mostly bad design decisions and poor domain knowledge
Yes, using NoSQL to avoid data migrations is a bad design decision. Usually created by poor general knowledge.
You could also consider renting an Oracle DB. Yep! Consider some unintuitive facts:
• It can be cheaper to use Oracle than MongoDB. There are companies that have migrated away from Mongo to Oracle to save money. This idea violates some of HN's most sacred memes, but there you go. Cloud databases are things you always pay for, even if they're based on open source code.
• Oracle supports NoSQL features including the MongoDB protocol. You can use the Mongo GUI tools to view and edit your data. Starting with NoSQL is very easy as a consequence.
• But... it also has "JSON duality views". You start with a collection of JSON documents and the database not only works out your JSON schemas through data entropy analysis, but can also refactor your documents into relational tables behind the scenes whilst preserving the JSON/REST oriented view e.g. with optimistic locking using etags. Queries on JSON DVs become SQL queries that join tables behind the scenes so you get the benefits of both NoSQL and SQL worlds (i.e. updating a sub-object in one place updates it in all places cheaply).
• If your startup has viral growth you won't have db scaling issues because Oracle DBs scale horizontally, and have a bunch of other neat performance tricks like automatically adding indexes you forgot you needed, you can materialize views, there are high performance transactional message queues etc.
So you get a nice smooth scale-up and transition from ad hoc "stuff some json into the db and hope for the best" to well typed data with schemas and properly normalized forms that benefit from all the features of SQL.
Edit: I just submitted a link to Joe Armstrong's Minimum Viable Programs article from 2014. If the response to my comment is about the enterprise and imaginary scaling problems, realize that those situations don't apply to some programming problems.
Why waste time screwing around with ad-hoc file reads, then?
I mean, what exactly are you buying by rolling your own?
What's special about SQLite is that it already solves most of the things you need for data persistence without adding the same kind of overhead or trade offs as Postgres or other persistence layers, and that it saves you from solving those problems yourself in your json text files...
Like by all means don't use SQLite in every project. I have projects where I just use files on the disk too. But it's kinda inane to pretend it's some kind of burdensome tool that adds so much overhead it's not worth it.
What overhead?
SQLite is literally more performant than fread/fwrite.
check_empty_vhosts () {
# Check which vhost adapter doesn't have any VTD mapped
start_sqlite
tosql "SELECT l.vios_name,l.vadapter_name FROM vios_vadapter AS l
LEFT OUTER JOIN vios_wwn_disk_vadapter_vtd AS r
USING (vadapter_name,vios_name)
WHERE r.vadapter_name IS NULL AND
r.vios_name IS NULL AND
l.vadapter_name LIKE 'vhost%';"
endsql
getsql
stop_sqlite
}
check_empty_vhosts_sh () {
# same as above, but on the shell
join -v 1 -t , -1 1 -2 1 \
<(while IFS=, read vio host slot; do
if [[ $host == vhost* ]]; then
print ${vio}_$host,$slot
fi
done < $VIO_ADAPTER_SLOT | sort -t , -k 1)\
<(while IFS=, read vio vhost vtd disk; do
if [[ $vhost == vhost* ]]; then
print ${vio}_$vhost
fi
done < $VIO_VHOST_VTD_DISK | sort -t , -k 1)
}Wait until you actually need it.
“Virding's First Rule of Programming: Any sufficiently complicated concurrent program in another language contains an ad hoc informally-specified bug-ridden slow implementation of half of Erlang.”
you should be squashing bugs related to your business logic, not core data storage. Local data storage on your one horizontally-scaling box is a solved problem using SQLite. Not to mention atomic backups?
What is more likely, if you are making good decisions, is that you'll reach a point where the simple approach will fail to meet your needs. If you use the same attitude again and choose the simplest solution based on your _need_, you'll have concrete knowledge and constraints that you can redesign for.
Surely it does? Otherwise you cannot trust the interface point with SQLite and you're no further ahead. SQLite being flawless doesn't mean much if you screw things up before getting to it.
Regardless of whether most apps have enough requests per second to "need" a database for performance reasons, these are extremely important topics for any app used by a real business.
This is also why many databases have persistence issues and can easily corrupt on-disk data on crash. Rocksdb on windows is a very simple example a couple years back. It was regularly having corruption issues when doing development with it.
There is one conclusion that I do not agree with. Near the end, the author lists cases where you will outgrow flat files. He then says that "None of these constraints apply to a lot of applications."
One of the constraints is "Multiple processes need to write at the same time." It turns out many early stage products need crons and message queues that execute on a separate worker. These multiple processes often need to write at the same time. You could finagle it so that the main server is the only one writing, but you'd introduce architectural complexity.
So while from the pure scale perspective I agree with the author, if you take a wider perspective, it's best to go with a database. And sqlite is a very sane choice.
If you need scale, cache the most often accessed data in memory and you have the best of both worlds.
My winning combo is sqlite + in-memory cache.
For our use case — merge, split, compress — we went fully stateless. Files are processed in memory and never stored. No database needed at all.
The only time a database becomes necessary is when you need user accounts, history, or async jobs for large files. For simple tools, a database is often just added complexity.
The real question isn't "do you need a database" but "do you need state" — and often the answer is no.
This is a solid takeaway and applies to a lot of domains. Great observation
I think a better way to ask this question is "does this application and its constraints necessitate a database? And if so, which database is the correct tool for this context?"
The very small bonus you get on small apps is hardly worth the time you spend redeveloping the wheel.
As the years went by, I expected the client to move to something better, but he just stuck with it until he died after about 20 years, the family took over and had everything redone (it now runs Wordpress).
The last time I checked, it had hundreds of thousands of orders and still had good performance. The evolution of hardware made this hack keep its performance well past what I had expected it to endure. I'm pretty sure SQLite would be just fine nowadays.
I should have charged him a percentage. Even if I had charged 0.5%, I would have made more money.
a jsonl file and a single go binary will literally outlive most startup runways.
also, the irony of a database gui company writing a post about how you dont actually need a database is pretty based.
But yeah, the page cache point is real and massively underappreciated. Modern infrastructure discourse skips past it almost entirely. A warm NVMe-backed file with the OS doing the caching is genuinely fast enough for most early-stage products.
weve basically been brainwashed to think we need kubernetes and 3 different databases just to serve a few thousand users. gotta burn those startup cloud credits somehow i guess.
mad respect for the honesty though, actually makes me want to check out db pro when i finally outgrow my flat files.
Similar sentiment.
Why setup a go binary and a json file? Just use google forms and move on, or pay someone for a dead simple form system so you can capture and commmunicate with customers.
People want to do the things that make them feel good - writing code to fit in just the right size, spending money to make themselves look cool, getting "the right setup for the future so we can scale to all the users in the world!" - most people don't consider the business case.
What they "need" is an interesting one because it requires a forecast of what the actual work to be done in the future is, and usually the head of any department pretends they do that when in reality they mostly manage a shared delusion about how great everything is going to go until reality hits.
I have worked for companies getting billions of hits a month and ones that I had to get the founder to admit there's maybe 10k users on earth for the product, and neither of them was good at planning based on "what they need".
I don't think it makes any sense to presume everyone around you is brainwashed and you are the only soul cursed with reasoning powers. Might it be possible that "we" are actually able to analyse tradeoffs and understand the value of, say, have complete control over deployments with out of the box support for things like deployment history, observability, rollback control, and infrastructure as code?
Or is it brainwashing?
Let's put your claim to the test. If you believe only brainwashed people could see value in things like SQLite or Kubernetes, what do you believe are reasonable choices for production environments?
Total hosting costs are £0 ($0) other than the domain name.
Different languages and stdlib methods can often spend time doing unexpected things that makes what looks like apples-to-apples comparisons not quite equivalent
I can use databases just fine, but will never be able to make wise decisions about table layouts, ORMs, migrations, backups, scaling.
I don't understand the culture of "oh we need to use this tool because that's what professionals use" when the team doesn't have the knowledge or discipline to do it right and the scale doesn't justify the complexity.
Memory of course, as you wrote, also seems reasonable in many cases.
In my (hypothetical, 'cause I never actually sat down and wrote that) case, I wanted the personal transactions in a month, and I realized I could just keep one single file per month, and read the whole thing at once (also 'cause the application would display the whole month at once).
Filesystems can be considered a key-value (or key-document) database. The funny thing about the example used in the link is that one could simply create a structure like `user/[id]/info.json` and directly access the user ID instead of running some file to find them -- again, just 'cause the examples used, search by name would be a pain, and one point where databases would handle things better.
Now that said, if there's value to the "database" being human readable/editable, json is still well worth a consideration. Dealing with even sqlite is a pain in the ass when you just need to tweak or read something, especially if you're not the dev.
How? With SQL is super easy to search, compare, and update data. That's what it’s built for.
However, if your all application state can be represented in a single json file of less than a dozen MB, yes, a database can be overkill.
Yes agreed, but it's usually a lot easier to find the filename part, especially if the application follows XDG. Sqlite databases are usually buried somewhere because they aren't expected to be looked at.
So my opinion has thoroughly shifted to "start with a database, and if you _really_ don't need one it'll be obvious.
But you probably do.
Overhead in any project is understanding it and onboarding new people to it. Keeping on "mainline" path is key to lower friction here. All 3 languages have well supported ORM that supports SQLite.
I ended up just buying a VPS, putting openclaw on it, and letting it Postgres my app.
I feel like this article is outdated since the invention of OpenClaw/Claude Opus level AI Agents. The difficulty is no longer programming.
If you want to do this for fun or for learning? Absolutely! I did my CS Masters thesis on SQL JOINS and tried building my own new JOIN indexing system (tl;dr: mine wasn't better). Learning is fun! Just don't recommend people build production systems like this.
Is this article trolling? It feels like trolling. I struggle to take an article seriously that conflates databases with database management systems.
A JSON file is a database. A CSV is a database. XML (shudder) is a database. PostgreSQL data files, I guess, are a database (and indexes and transaction logs).
They never actually posit a scenario in which rolling your own DBMS makes sense (the only pro is "hand rolled binary search is faster than SQLite"), and their "When you might need" a DBMS misses all the scenarios, the addition of which would cause the conclusion to round to "just start with SQLite".
It should basically be "if you have an entirely read-only system on a single server/container/whatever" then use JSON files. I won't even argue with that.
Nobody - and I mean nobody - is running a production system processing hundreds of thousands of requests per second off of a single JSON file. I mean, if req/sec is the only consideration, at that point just cache everything to flat HTML files! Node and Typescript and code at all is unnecessary complexity.
PostgreSQL (MySQL, et al) is a DBMS (DataBase Management System). It might sound pedantic but the "MS" part is the thing you're building in code:
concurrency, access controls, backups, transactions: recovery, rollback, committing, etc., ability to do aggregations, joins, indexing, arbitrary queries, etc. etc.
These are not just "nice to have" in the vast, vast majority of projects.
"The cases where you'll outgrow flat files:"
Please add "you just want to get shit done and never have to build your own database management system". Which should be just about everybody.
If your app is meaningfully successful - and I mean more than just like a vibe-coded prototype - it will break. It will break in both spectacular ways that wake you up at 2AM and it will break in subtle ways that you won't know about until you realize something terrible has happened and you lost your data.
Didn't we just have this discussion like yesterday (https://ultrathink.art/blog/sqlite-in-production-lessons)?
It feels like we're throwing away 50 years of collective knowledge, skills, and experience because it "is faster" (and in the same breath note that nobody is gonna hit these req/sec.)
I know, it's really, really hard to type `yarn add sqlite3` and then `SELECT * FROM foo WHERE bar='baz'`. You're right, it's so much easier writing your own binary search and indexing logic and reordering files and query language.
Not to mention now you need a AGENTS.md that says "We use our own home-grown database nonsense if you want to query the JSON file in a different way just generate more code." - NOT using standard components that LLMs know backwards-and-forwards? Gonna have a bad time. Enjoy burning your token budget on useless, counter-productive code.
This is madness.
Even it's postgres, it is still a file on disk. If there is need something like like partitioning the data, it is much more easier to write the code that partitions the data.
If there is a need to adding something with textinputs, checkboxes etc, database with their admin tools may be a good thing. If the data is something that imported exported etc, database may be a good thing too. But still I don't believe such cases, in my ten something years of software development career, something like that never happened.
…and it won’t get better anytime soon.