This often isn't related to a monolith vs microservice comparison. Large enterprises and institutions tend to run a lot of completely separate applications, which then end up sharing database infrastructure unnecessarily. Think of universities, for example.

Oracle extends the problem to the opposite end of microservices, by encouraging monolith DB consolidation, with unrelated monolith applications on the same db cluster for purely budgetary reasons.

> unrelated monolith applications on the same db cluster

If your "db cluster" is split into containers on one VM as you would do in any other cloud (because VMs are expensive), then you would have the same problem.

> encouraging monolith DB consolidation

Does it? I don't think so. I've worked with Oracle's stuff and the only real difference between Oracle Cloud and other clouds is that Oracle cloud is more expensive overall. There's nothing stopping you from running virtual machines and kubernetes in the same way you'd run it in any other cloud.

Yep. And then when the DBs are already on the same servers, when there's a need to connect previously unrelated apps to some master data, a shortcut presents itself. The DBA thinks: After all, why not? Why shouldn't I take it?