There is a subreddit for elder scrolls lore called /r/teslore, but for more shit posting lore content there was /r/shittyteslore, but that subreddit went weird so people made true shitty tes lore (/r/truestl).
select distinct thumbnail_url as url from post where not local and thumbnail_url like 'https://campfyre.nickwebster.dev/pictrs%'
(replace with your instance's url)
I then sent delete requests to /internal/purge on pictrs to delete all of those old thumbnails, which cleared out a lot of space. After deleting the thumbnails I ran an UPDATE query to set all of those old thumbnail URLs to null in the DB. I also patched the version of lemmy that I run to stop caching thumbnails in the future. Hope this helps!
If you want to make one on my instance (or any other) I'm happy to help out with it