Deleting Post Revisions: do NOT use the a,b,c JOIN code you see everywhere

Post revisions bother some people, especially on larger sites because they add lots of rows to wp_posts. A common bit of MySQL code posted in these forums, plugins and elsewhere goes like this:

### do not use: ###
# DELETE a,b,c
# FROM wp_posts a
# LEFT JOIN wp_term_relationships b ON (a.ID = b.object_id)
# LEFT JOIN wp_postmeta c ON (a.ID = c.post_id)
# WHERE a.post_type = 'revision';

The problem here is that wp_term_relationships is used for both posts and links, two different tables. Sometimes the object_id refers to wp_links.link_id, not wp_posts.ID. And object_id‘s are not unique in wp_term_relationships. So there is a chance, especially with lower-numbered wp_post.ID‘s, that you will delete a relationship needed to make Dashboard / Links work. The DELETE will remove two rows that match object_id, one for a post and one for a link.

One plugin with this bug is
https://www.ads-software.com/plugins/better-delete-revision/

Another plugin just deletes revisions and does not clean up meta and terms at all, which is not ideal:
https://www.ads-software.com/plugins/delete-revision/

These plugins try to do things the right way, by using WP’s own term functions:
https://www.ads-software.com/plugins/rvg-optimize-database/
https://www.ads-software.com/plugins/revision-control/

Here is a proposal to put a revision deletion function in WP core:
https://www.ads-software.com/ideas/topic/native-function-to-delete-post-revisions