Does Post Type Switcher store the redirection information?

[WindingWinter]

I use Post Type Switcher to switch some of my blog post type from 'post' to 'docs' ( a custom post type), thus the URL is changed from /blog/* to /docs/*. I note that the original post at /blog/*( eg: /blog/someinfo is automatically (301) redirect to/docs/*( eg: from /blog/someinfo to /docs/someinfo). When I use a redirection check website, I found that the redirection is done on WordPress level.

Changing the post type from 'post' to 'page' also has the same effect.

I thought that this is well explained by the WordPress creates redirect from old URL after changing slug question. So I use SELECT * FROM wp_postmeta where meta_key = "_wp_old_slug" to confirm that the redirection is indeed stored there. But to my huge surprise, I can't find anything that has anything to do with the above redirection.

( If on the other hand, I just change the slug manually and not changing the Post Type, like changing the url from /blog/someinfo to /blog/someinfo-2, then I would see something at meta_value column, and hence I can rest assure that the redirection is real and permanent).

This creates a confusion for me. Does Post Type Switcher store the redirection information in the WordPress database? If yes, at where? I go through the source code, and it seems that the plugin only changes the database only once, at one type, at set_post_type, so no redirection information is written.

How the redirection is accomplished? Anyone can shed any lights on this?

[JJJ]

Great question @WindingWinter!

Here's how WordPress handles this (without the Post Type Switcher needing to do anything)

https://developer.wordpress.org/reference/functions/redirect_canonical/

It's pretty awesome!