Does anyone know how to optimize this query?
SELECT planbook.*,
COUNT(pb_unit_id) AS total_units,
COUNT(pb_lsn_id) AS total_lessons
FROM planbook
LEFT JOIN planbook_unit ON pb_unit_pb_id = pb_id
LEFT JOIN planbook_lesson ON pb_lsn_pb_id = pb_id
WHERE pb_site_id = 1
GROUP BY pb_id
SELECT planbook.*,
( SELECT COUNT(*) FROM planbook_unit
WHERE pb_unit_pb_id = planbook.pb_id ) AS total_units,
( SELECT COUNT(*) FROM planbook_lesson
WHERE pb_lsn_pb_id = planbook.pb_id ) AS total_lessons
FROM planbook
WHERE pb_site_id = 1
planbook: INDEX(pb_site_id)
planbook_unit: INDEX(pb_unit_pb_id)
planbook_lesson: INDEX(pb_lsn_pb_id)