sql查询在辅助表上非常慢

Question

我有以下查询，其功能类似于魅力，但是当时表“ci_falsepositives”变满，查询变得非常慢。

有没有人有更好的解决方案来加快速度？感谢...

SELECT * , matches - falsepositives AS hits 
  FROM (SELECT c.*, 
               IFNULL( p.total, 0 ) AS matches, 
               (SELECT COUNT( * ) 
                  FROM ci_falsepositives n 
                 WHERE n.addressbook_id = c.reference 
                   AND n.sanction_key IN (SELECT sanction_key 
                                            FROM ci_matched_sanctions)) AS falsepositives 
          FROM ci_address_book c 
     LEFT JOIN ( SELECT addressbook_id, 
                        COUNT( match_id ) AS total 
                   FROM ci_matched_sanctions 
               GROUP BY addressbook_id) AS p ON c.id = p.addressbook_id) S 
ORDER BY folder asc, lastchecked DESC 
   LIMIT 0, 15