Hi,
thanks for you optimal plugin, but there's an issue on the sitemap module;
when it's generating a sitemap there's a query that load all the four cpu of my vps and get down my website:
\wordpress-seo\inc\class-sitemaps.php
SELECT l.ID, post_title, post_content, post_name, post_author, post_parent, post_modified_gmt, post_date, post_date_gmt FROM ( SELECT ID FROM $wpdb->posts {$join_filter} WHERE post_status = '%s' AND post_password = '' AND post_type = '%s' AND post_author != 0 AND post_date != '0000-00-00 00:00:00' {$where_filter} ORDER BY post_modified ASC LIMIT %d OFFSET %d ) o JOIN $wpdb->posts l ON l.ID = o.ID ORDER BY l.ID
I've the last version of WP with W3 Total Cache on a Debian 7 with Nginx, PHP5-FPM and MariaDB 10.1. My db have +400k posts.