And this right here is why PostgreSQL will never overtake MySQL and its forks. The entire industry is sick of these excuses regarding process-per-client instead of a proper multi-threaded model. There may have been a valid argument for this 15 years ago, but not anymore.
Your definition of "reasonable number of long-lived connections" is anything but reasonable. Then "connection pools address a lot of the other cases", when a connection pool/bouncer is unwanted, unwarranted, and just adds another point of failure that needs to be deployed and maintained.
Firstly, it's not the goal of the PostgreSQL project to overtake MySQL or other databases, but to serve the existing/new users. This also means we're investing the development effort in a the highest benefit / effort ratio. Even if switching from process-based to thread-based model improved the per-connection overhead, the amount of work needed is so huge the benefit / effort ratio is so utterly awful no one is going to do it. There are always better ways to invest the time / effort. Especially when there are practical solution / workarounds like connection pools.
Secondly, every architecture has pros/cons, and switching from processes to threads might help in this respect but there are other consequences where the process model is superior (some of which were already mentioned). Focusing on just this particular bit while ignoring the other trade-offs is rather misleading.
And no, the arguments did not really disappear. To some extent this is about the programming model (locking etc.), and that did not really change over time. Also, PostgreSQL supports platforms, some of which may not have particularly great threading support.
I'm not claiming there are no workloads / systems that actually need that many long-lived connections without a connection pool. In my experience it's usually "We don't want to change the app, you have to change the DB!" but fine - then maybe PostgreSQL is not the right match for that application.
> Even if switching from process-based to thread-based model improved the per-connection overhead, the amount of work needed is so huge the benefit / effort ratio is so utterly awful no one is going to do it.
Then other products will emerge and overtake some of PostreSQL's marketshare in the long run. It's already happening in fact. Just like more efficient and easier to configure webservers like nginx and caddy are gaining marketshare over Apache httpd.
I love PostgreSQL and don't want to see it becoming the next Apache httpd, slowly but surely fading. Perhaps FAANGs could fund such refactor.
Perhaps a cheaper solution was to incorporate pgBouncer inside PostgreSQL so it would naturally sit in front of PostreSQL in the default installation without extra configuration.
> Then other products will emerge and overtake some of PostreSQL's marketshare in the long run. It's already happening in fact. Just like more efficient and easier to configure webservers like nginx and caddy are gaining marketshare over Apache httpd.
Maybe, we'll see.
It however assumes the other (thread-based) architecture is somewhat universally better, and I doubt that's how it works. It might help the workloads actually requiring many connections to some extent, but it's also likely to hurt other workloads for which the current architecture works just fine.
But let's assume we decide to do that - such change would be a massive shift in programming paradigm (both internally and for extensions developed by 3rd parties) and would probably require multiple years. That's a huge investment of time/effort, with a lot of complexity, risks and very limited benefits until it's done. I'd bet there'll always be a feature with better cost/benefit ratio.
So reworking the other architecture might actually gain us some users but loose others, and drain insane amount of development resources.
> Perhaps a cheaper solution was to incorporate pgBouncer inside PostgreSQL so it would naturally sit in front of PostreSQL in the default installation without extra configuration.
Yes, I already mentioned that's quite likely to happen. There has already been a patch / project to do exactly that, but it didn't make it into PG14.
Your definition of "reasonable number of long-lived connections" is anything but reasonable. Then "connection pools address a lot of the other cases", when a connection pool/bouncer is unwanted, unwarranted, and just adds another point of failure that needs to be deployed and maintained.