What situation RDBMS need to vm or docker virtualization?
Personally, I really like the idea of putting a golden set of data in a VM or container for QA testing. Spin up a new VM/container for each project and you can test it in isolation. When testing is complete, it goes away cleanly. You can do the same thing for development: Think git branches.
I can't tell you how many times I've had projects look like they were failing because someone mucked up the data in the dev/qa environment to test a different project.