That’s why there are billions of SQLite databases right?

SQLite is likely used more than all other database engines combined. Billions and billions of copies of SQLite exist in the wild. SQLite is found in:

Every Android device Every iPhone and iOS device Every Mac Every Windows 10/11 installation Every Firefox, Chrome, and Safari web browser Every instance of Skype Every instance of iTunes Every Dropbox client Every TurboTax and QuickBooks PHP and Python Most television sets and set-top cable boxes Most automotive multimedia systems Countless millions of other applications

https://sqlite.org/mostdeployed.html

I had very good results giving 1 SQL DB per go routine, so the accesses were serialized up front, on a very high volume (130K requests/second) service. Exact transactionality was not a product goal, and the SQLite was just to backup the in memory state. If we lost a little due to abend or something, that was ok (although for normal maintenance it caught SIGTERM and stopped the listen and then waited for in flight calls and then flushed the remaining changes to SQLite; then on startup it would read the SQLite into memory to populate before taking the listen; persistent storage across container runs, and never both reads and writes to the same file at the same time. (It also just closed the DB and opened a new one when it hit some limit of rows, so as not to fill the disk; the max size of the SQLite corresponded to the max size of the LRU map being served from in memory; then it just flipped A / B between "a full memory worth of data stored" and "the currently updating state." A lot easier than having to write out proto bufs to disk or whatever I would have done for transient (during restarts/maintenance) persistence.

You seem to have a rather limited understanding of what kinds of concurrency exist and how those needs are best met. Whether something is a server or not is not very relevant to this discussion.

SQLite is an excellent production db for many real world workloads, as has been widely documented. It is very different to Postgres, so requires learning a whole new skill set.

One way to think about it is that SQLite can work well for the parts of your system where there is naturally strong partitioning.

> This is a foundational principle of computer science

How exactly is this a foundational principle of computer science?

Computer science no more get its hands dirty with concrete software than physics primarily being about building bridges.

It is not «a foundational principle of computer science».

Isn't concurrency also limited by your machines disk speed for writes, what difference does it make if you write sequentially vs concurrently? Why does concurrency even matter for databases?

Well if you run a tiny single-threaded app then SQLite is a nice simplification over spinning up a separate machine for Postgres.

It's almost as if Postgres isn't perfect, and one size shoe doesn't fit all.

Some people want some of the benefits you get from SQLite.

SQLite is obviously not perfect, but it's an incredible piece of software, and people regularly find good ways to make use of an excellent pieces of software.

sqlite is more like a file format than a database. it competes with .xlsx.

> "SQLite for everything" crowd is a little bit inexperienced.

every time i see it in a real application, it becomes a huge focus of issues (for example: jellyfin, hermes, openwebui, comfyui)

I absolutely 100% do not understand it either. At all. Every time I try to over the last year or two I come away with the conclusion its something that sounds cool (to me too!) but is guaranteed to cause more problems than more obvious solutions.

That being said I'd kill for someone who used it and benefited to explain it to me in a practical sense. (specifically where syncing is involved, and syncing a subset of the SQLite is necessary. If it's "just" a document store thats treated like a blob for syncing/backup, that's familiar. If it's all in one storage but only local, that's familiar.)

Re: TFA, I guess it would have helped if I knew what Obelisk was, which is on me, and a more in-depth explanation of how this ties into AI/agents, which is on the industry/writer.

So teach them. If you want to bring up computer science fundamentals, the question is where does SQLite sit with regards to the CAP theorem. Consistency, Availability, and Partition tolerance. SQLite isn't a distributed system, so there are no partitions to tolerate, so it's a CA system. Other databases make different tradeoffs. For systems that don't need concurrent writes, SQLite is pretty great! There are no users to manage, no permissions, no daemon to run, no server and port to mix up. Just open a file on disk using a library.