You don't seem to have any experience with solid, mature RDBMSs like PostgreSQL or Oracle or SQL Server. MySQL sucks in so many ways and all the other names you mentioned are not RDBMSs. People running large numbers of (for example) MS SQL Servers will tell you that they are ridiculously robust and mature and do NOT randomly crash in the middle of the night. And even when your hardware lets you down your hot failover machine is ready to take over without skipping a beat.
Magic bullet? These systems are the closest you can find in the world of software.
<sigh> Or when the Oracle SCN advances too quickly, causing random systems to refuse connections or crash outright. Just because software is large, supported, and mature doesn't mean it is free of serious design flaws.
[Edit:] Don't get me wrong, Oracle's DBs are serious business; an incredible feat of engineering. If I could afford them I'd probably use them more often. But everything in this business is a cost tradeoff--in licenses, in dev time, in risk.
Aware Postgres is free: it's an excellent database and I've used it successfully (like most of the other tools I've mentioned.) It also has spectacular failure modes; though the only ones I've personally encountered were around vacuuming.
So if these incredibly mature and robust systems are an 'operational nightmare' I'd like to hear what software systems ARE up to your operational standards?
How often did you manage to spectacularly fail PostgreSQL to qualify it an 'operational nightmare'?
Magic bullet? These systems are the closest you can find in the world of software.