[hilariously]

Yes, it would. Basically every serious database tries to allocate everything and more - back in the day we'd just allocate VMs on the machine even with the overhead because knowing it cannot leave its constraints and would work within them was worth the cost.

[guenthert]

There are many reasons to use a dedicated host (or VM) for a DB server, but if only the accessible memory needs to be limited a container is the simpler, more efficient tool. Said that, I would expect to be able to configure how much memory a DB process is allowed to allocate. I remember distinctly that PostgreSQL allows such. But of course both can be configured simultaneously, a belts&suspenders approach if you will.

Whether failed transactions are actually so much more desirable than a OOM-killed process isn't quite obvious, but it might be easier to troubleshoot.