Baffled, I just went into wp-admin and changed the Post Slug to something new, this was reflected in the url, so it is example.com/my-new-post-slug
The old one was example.com/bad-name
Whats nice, is if I go to the old one, I get a 301 redirect, but I have no idea how WP is pulling this off. Looking at the DB schema, I see nothing in there that could allow it to know this. I toggled off all my plug-ins so I know those are not doing this either.
How does this work?