Correct. So we're talking about in memory databases like MongoDb, and all of the things I listed here are true about MongoDb. For example, MongoDb migrated their database memory manager away from mmap and towards a custom memory manager (point being that gc and memory management for databases is not something you can just use jvm or operating system constructs for)

https://docs.rocket.chat/installation/docker-containers/mong...

I'm happy to justify every single point I made with research papers.

Lastly I know I came off as a bit condescending. Just having a bad day, nothing personal. But you should read more about in mem dbs.