I have over 800 url-aliases on my site and I would like to delete them all. I haven't found any way to do it in the admin interface other than clicking delete on each and every one of them. Obviously that's not a viable solution for that many aliases.

Did I miss something in the interface?
Or do I have to do it manually in the database? I found the "url_alias" table, but I'm hesitant to empty it before I know if the table entries are used somewhere else.

Some help, pretty please :)