I want to create two workspace, one for myself with synchronization to the remote end, one for my work which just keep local. Please add such support, I really need it.
You can use the (unsupported) --profile argument. More info here [Feature Request] run multiple instances of Joplin · Issue #591 · laurent22/joplin · GitHub
If you are using Windows then you can use the portable app which creates its own database in the directory you run it from