We need an automated check to ensure that if changes are made to the grade tables that the history tables are kept up to date. For example changes to grade_items most likely want to be reflected in grade_items_history.
We need to do two things:
1) if this isnt covered by an existing test then make sure the tables match those described in install.xml
2) ensure that the grade tables and the grade history tables match up
This may help. http://pastebin.com/BPhvVSCi