Admin & blog not displaying posts for category

Our wordpress database is fairly large with 212K posts, 48K tags and 1,144,521 wp_term_relationship records. We recently imported a large number of records which bloated the term relationships. We have one category with over 207K posts. When we browse to this category (Categories > Posts) in the admin now, it shows “no posts found”, also, on our website the category loop displays no records now.

Anyone have any clue why this would happen?