extensions.joomla.org/extensions/hosting...base-management/2867

This will save everyone a little headache.

It's called EasySQL and has quite a few great benefits, but #1 for this thread is the ability to change jos_ to master_ in about 2 seconds.

All you gotta do is change your permissions on configuration.php to 744 (that's what I did anyway), install the component, go to component, click drop the down menu and select REPLACE PREFIX `master_` TO, then simply put what you want to change it to and click Exec SQL... Done! Instantly changes everything.

Just wanted to clarify that it says REPLACE PREFIX `jos_` TO
and that's at the very bottom of the "Command" drop-down menu.

Thanks for your trick, this extension is perfect for that purpose!
Haope now I can achieve to configgure JMS. Not so easy...