DELETE FROM wp_options WHERE option_name LIKE '_transient_rss_%';
DELETE FROM wp_options WHERE option_name LIKE '_transient_timeout_rss%';
DELETE FROM wp_options WHERE option_name LIKE '_transient_feed_%';
DELETE FROM wp_options WHERE option_name LIKE '_transient_timeout_feed_%';
DELETE FROM wp_options WHERE option_name LIKE '_site_transient_browser_%';
DELETE FROM wp_options WHERE option_name LIKE '_site_transient_timeout_browser_%';
DELETE FROM wp_postmeta WHERE meta_key = '_edit_lock';
DELETE FROM wp_postmeta WHERE meta_key = '_edit_last';
DELETE FROM wp_postmeta WHERE meta_key = '_wp_old_slug';
DELETE  FROM wp_commentmeta WHERE meta_key LIKE  '%akismet%' ;
DELETE  FROM wp_commentmeta WHERE comment_id NOT  IN  ( SELECT comment_id FROM wp_comments ) ;
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';
OPTIMIZE TABLE wp_options, wp_postmeta, wp_commentmeta, wp_posts, wp_term_relationships;