SELECT COUNT(*) FROM (
SELECT author_id, author_email, author_meta_type, author_meta_vchar_idx, author_modified_on
FROM mt_author as t1
LEFT OUTER JOIN mt_author_meta as t2
ON (t1.author_id = t2.author_meta_author_id AND t2.author_meta_type='field.ars_opt_in')
UNION ALL

SELECT author_id, author_email, author_meta_type, author_meta_vchar_idx, author_modified_on
FROM mt_author as t1
LEFT OUTER JOIN mt_author_meta as t2
ON (t1.author_id = t2.author_meta_author_id AND t2.author_meta_type='field.partner_opt_in')

ORDER by author_id Limit 0,8)