Jupgrade database tables
From Joomla! Documentation
Porting only DB from Joomla 2.5 jupgrade to Joomla 2.5 fresh install[edit]
In my experience doing this resulted in a broken installation with only a few lines of code being printed out to the browser. There were no debug errors and both installations used the same version of Joomla 2.5 with the same template. If someone could shed some more light on this it would be helpful.