You are also missing the point and in the same way.
You are at A, you want to go to C. We are debating which B to pick between:
1. a filesystem + implementing library over that to cover the interface between A and C.
2. Postgres (which is the same as above - just not invented here)
Now, both of you are imagining a world where #2 somehow implies more complexity and also more second order effects than #1 would.
Nobody uses all of Postgres, but the cost of not using more than 1% of what's available is hardly larger than implementing that 1% yourself for most use cases. And please don't make the misstake of thinking that I'm trying to sell Postgres over any other database product - this is all to do with the worse is better idea that so many of you cultivate.
Postgres isn't a webserver that can handle 1m http GET requests per second; it doesn't distribute data from 30 event collectors to a reporting database without configuration. *Other stuff needs to be written to satisfy the business.* That's life.
> both of you are imagining a world where #2 somehow implies more complexity and also more second order effects than #1 would.
Most studies into product resolution agree that there's zero difference (from a pass/fail perspective) between writing it yourself or trying to reuse third-party applications. Here's one from some quick ddging: https://standishgroup.com/sample_research_files/CHAOSReport2... and see the resolution of all software products surveyed (page 6).
That means that if you can, it is still cheaper to build new software and test it than to try to use Postgres and scale it, because once software is written the cost is (effectively) zero, whereas the cost to support Postgres is a body -- that I might only be able to use 1% of, and that I might need to hire two so that one can go on holiday sometime, with a real salary that we need to pay.
Now maybe you're working for a company whose software never gets finished. In that case, by all means use Postgres in your application, since you can share the churn on that part with every other person using Postgres in the world, but I'm going kayaking today.
Postgres is also using the file system, it’s just got some extra layers in-front like networking and authentication.
People often refer to those “extra layers” as complexity.
> how come?
Why is it that more code is more stuff that can go wrong? That’s just how it is.