Changing user of post by changing ‘post_author’ field in ‘wp_posts’ table not taking effect. Where is the real post author info kept?

the real author id is stored in… post_author in the posts table. not sure what’s going on in your case. I’ve just created a new user now and changed some post_author ids to this new user directly in the database and it’s showing immediately when I refresh the admin interface. maybe some sort of cache situation you’ve got happening.