Howard Miller

Upload the users using the CLI option?

https://docs.moodle.org/405/en/Upload_users#Upload_users_via_CLI

 

You could also try Moosh (https://moosh-online.com/commands/). Probably the 'user-create' command.

Firstly, I am moving this to Hardware and performance.

Secondly, I just don't believe you. I am struggling to envision 1.5 million users actively using a Moodle site at THE SAME TIME. Which is what "concurrent" means to me. I think what Moodle would or wouldn't support would be just one of your worries getting that to work. Where are you planning on running this and how good is the network connectivity - and so on?

Have a look at...

Site administration > Users > User policies > Hide user fields

LMGTFY....

https://moodle.academy/course/index.php?categoryid=4

I'm going to assume that you mean coding somewhere outside of Moodle, as you never have to refer to the database name explicitly in Moodle code.

If that's the case then, yes, you'll be fine. You only need to change the name (to the new name) in config.php.

I would only add that, in MySQL, there's no direct way to rename a database. Again, I suspect you know that.