God forbid if you do it. You’ll pretty much lose all your conent and have to recreate the site. (Unless you want to dig into the database for the latest version history.)
Yes, somehow the Admin UI allows it to happen. I know…I did it. And once you do that, after you manage to snag your content from the database, you should probably just reinstall the whole site. (Or at least figure out how to purge all the content-related records. I now have orphaned records. And in one case I had to manually replace the “slug” value on that orphaned record via direct SQL so that I could change the permalink (same thing) on another page. An orphaned, lost record has “about”, so everytime I tried to use “about” (on the new page I was having to recreate) it would append five random characters. Nice to avoid the duplicates, but took me ten minutes to solve.
Is there a database cleanup utility? Or a SQL script available? (MySQL in this case.)