Well, it's DB for sure, but what does this link:
More information about this errorsay?
The DB user for the Moodle DB should have pretty much permissions to do all things MySQL. Think I'd check on that first.
The DB is mysql.
This query: mysql> select Alter_priv from user where user='root';
You replace the 'root' above to the DB user you see in your config.php file.
'spirit of sharing', Ken