Ok but the article you're replying in the comments to says "SQLite is all you need for nearly everything", and what the comment you're replying to is describing is, to use their very apt word choice, entirely ordinary.
So how do we square this circle of somebody being told both "SQLite is all you need for everything" and "it is not a good option for your totally ordinary use case"?
I think the answer is that you are a different person than the author of the article and you don't agree with the article's claim. Which, great, that was irskep's entire point!
I tend to agree with irskep that this SQLite architecture is really interesting, but I also don't quite get it. There seem to be a lot of missing details for totally bog standard applications, that people frustratingly seem to just not even mention - like the migrations thing, or how to do zero downtime deploys in general, or a few other things - as if those concepts are irrelevant or uncommon. But they aren't, they're important and typical things to think about.
"In contrast to many other database management systems, SQLite is not a client-server database engine, but you actually very rarely need that. If your application software runs on the same physical machine as the database, which is what most small to medium sized web applications does, then you probably only need SQLite."
That's how we square it. It's right there in the article.
(Nearly) zero down time is a common requirement. Can a live backup be made while transactions are in progress? That appears to be the case. What about schema changes? Can columns or indexes be added without interfering with access to the tables in question? And so on.
Are we still talking about small to medium web apps ? I'm sorry but if HN goes down things will be OK. In fact, there is a very large majority of services that can go down go down and things will still be OK.
Rather than applications you've worked on (many of us spend years on end working on a narrow range of applications), consider software you use (most of us flip between multiple applications every day spanning the gamut of uses). Ignore, for a moment, whatever you know about their implementation, and focus on the user-facing functionality.
Do even half of them logically communication between application nodes?
(Consider that there is still a rich class of software that is fully capable of running locally on the "client"'s computer!)
- Browsers
- Messengers
- The telephone directory of your cellphone
- SMS apps
- The sqlite.org Website
- ...
?
edit: when I worked as a sysadmin we would have to schedule outages for updating apps that were designed for zero downtime anyways because those were the processes of the organisation.
Even for online business some downtime might be acceptable or even preferred. I used to work for a company that made most of it's money through a website and it would take the site offline for 8 hours a few weeks before important events to run a full scale load test on the production infrastructure.
Another place I worked we had to schedule downtime even when updating applications that were designed for zero downtime.
I have never worked a place that didn't allow for downtime or even heard of such a place other than the big tech companies.
Not only is that a pain for whoever is monitoring the deployment, but now if the deployment breaks something you're going to have to go wake up all of the relevant stakeholders, if you even know who they are.
Not to say late night deployments are never justified, but definitely not something devs want to be doing regularly.
* Hobby apps designed for yourself and your friends.
* Hobby apps that you hope will become products but probably won't achieve traction.
* Apps where you're trying a new stack or framework.
* Annotation apps for academia.
Basically, every single app written by people who aren't doing internet facing web dev as their core engineering function.
Also intranet apps as other commenter mentioned.
I'm not sure exactly what you have in mind for annotation apps for academia - things like zotero that run client side? If so, sure, there is a big world of client side software where a database is useful, and I think SQLite (or DuckDB) seems like a no brainer there.
I don't really agree about intranet apps, which are often even more critical to the people using them than an arbitrary consumer app. But I'll grant that for a company that spans a small number of time zones, you can at least have downtime windows outside work hours.
In any case, as I've said all over this thread, the only disagreement here is over what kinds of software is "most". And my intuition for "most" is based on my experience working on and using applications where a lot of effort is made to keep the thing running all the time while still evolving it. Maybe you're all right that "most" software isn't like that.