During design/dev I created a bunch of matrix fields that I have since decided not to use. I have deleted the fields, however, I notice that the matrix tables are still in the database. Is it safe to delete these manually, or is there some other cleanup that needs to happen as well (i.e. references within another table, etc.)?
Update: The problem is caused when changing the fieldtype from a matrix field to another field type, rather than deleting the field altogether, and creating a new one. Even if the field is subsequently deleted, the matrix tables will still remain, which results in orphaned data in the DB.