In my experience being careful with the queries is harder and/or more expensive. Developer time is either very expensive or you just don't have the right develo

In my experience being careful with the queries is harder and/or more expensive. Developer time is either very expensive or you just don't have the right developers. It also depends a lot what kind of money you can throw around. Are you a big fat insurance company? Music business? Bank? You are just gonna throw money at Oracle and your hardware vendor and its gonna scale (thinking 10-ish years back into my past here as an example). I think we came from like 4GB of RAM on the DB and a couple of CPUs with single path i/o. Could have spent ages optimizing all the different workloads. And this was already using read only replicas heavily for around the globe acceleration. This internal app was used 24/7 from different places in the world tho heaviest usage was Europe/US timezone. Instead they got 128GB of RAM, 16 cores IIRC and 4-path i/o (still spinning disk w/ SCSI at the time). Sure it cost a lot I'm sure. But I doubt it cost more than a year's salary of _one_ of us developers. And optimization would've required the application developers, the backend batch job developers and the (shared resource) DB admins to work on a multitude of workloads and use cases to analyze and optimize. FF to my current job with lots and lots of but mainly smaller customers. One DB instance per per customer would be a lot of overhead. We do one schema per customer on PostgreSQL right now with sharding.