I need to change over 100 subcategories, in fact move them to another category, if I use the admin interface, I have to go one by one, which will be too slow(and prone to errors). So I want to know how they are related in the database, which index I have to modify to make the subcategories point to their new category, as none of the products are linked, there should be no problems if I do that(as far as products linked to master categories are concerned). My guess is, there is an index that points the subcat to their parent, but as I don't know all the tables relationships, and I don't want to make a mess by modifying the wrong thing or do a partial modification, then which tables I have to look, if I want to accomplish this?