Некоторые советы по оптимизации
SELECT wp_posts.ID
FROM wp_posts
-- LEFT -- probably misleading
JOIN wp_term_relationships
ON (wp_posts.ID = wp_term_relationships.object_id)
WHERE
-- 1=1 AND -- junk
( wp_term_relationships.term_taxonomy_id IN (4,5,6,
7,8,9,10,11,12,13,14,15,16,17,18,....,5000) )
-- Could that changed to be "BETWEEN 4 and 5000" ?
AND wp_posts.post_type = 'post'
AND (wp_posts.post_status = 'publish')
GROUP BY wp_posts.ID
ORDER BY wp_posts.ID DESC -- same(?) effect, much better optimization
LIMIT 0, 30
Индексы:
wp_posts: (post_type, post_status, ID)
wp_term_relationships: (object_id, term_taxonomy_id)