Howard Miller

Yep - agreed. I enabled database debugging and it's generating thousands of DB calls concerned with quiz statistics. The stats block is disabled.

Is it ridiculous to ask why quiz statistics should kill the site when it's enabled? TBH... I'd never heard of quiz statistics until 10 mins ago. 

Weirdly it doesn't seem to do it on a test copy of our live site. 

My guess would be an error in an optional plugin. If you have installed any non-core plugins or themes, get rid of them.

I don't think you can.

I checked the roles capabilities and there's nothing that specifically allows/prevents that particular scenario.

We have managed to get deeply philosophical here. I'm probably going to make it worse... you might want to have a read of, https://moodle.org/mod/forum/discuss.php?d=447628

If money were no object, the simple thing is probably to buy a Linux VM of some sort off AWS, DigitalOcean or whoever and you can more or less run any versions of the OS software you like. You can even use their database, cache, file server, backup (and so on) services if you want. However, to get enough computing power to run a decent size Moodle site is going to be relatively costly.

As mentioned in the other thread, you can probably reduce this by looking at containers (most well-known hosts have some variation on this) but you've just increased the complexity of the project by an order of magnitude.

At the end of the day, it's like buying gas or electricity - there's a little meter ticking away somewhere and someone will charge you for the stuff you use. Sometimes quite a lot.