這個查詢/數據庫無法正常工作在一起

Question

這裏有一個查詢：

SELECT 
    *, 
    COUNT(*) as `numauth` 
FROM `favorites` as `f1` 
INNER JOIN `story` as `s1` ON `f1`.`story_id` = `s1`.`story_id` 
WHERE `f1`.`story_id` != '".addslashes($_REQUEST['storyid'])."' 
    AND `f1`.`story_id` != '".addslashes($_REQUEST['storyid2'])."' 
    AND EXISTS (
       SELECT 1 FROM `favorites` as `f2` 
       WHERE `story_id` = '".addslashes($_REQUEST['storyid'])."' 
       AND `f2`.`auth_id` = `f1`.`auth_id`) 
       AND EXISTS (
          SELECT 1 FROM `favorites` as `f3` 
          WHERE `story_id` = '".addslashes($_REQUEST['storyid2'])."' 
          AND `f3`.`auth_id` = `f1`.`auth_id`) 
          AND NOT EXISTS (
              SELECT 1 FROM `favorites` as `f4` 
              WHERE `story_id` = 
              '".addslashes($_REQUEST['exclude'])."'                         
              `f4`.`auth_id` = `f1`.`auth_id`) 
GROUP BY `f1`.`story_id` 
ORDER BY `numauth` DESC, `story_words` DESC 

而這裏的表的說明...

CREATE TABLE IF NOT EXISTS `favorites` (
    `fav_id` int(10) unsigned NOT NULL AUTO_INCREMENT, 
    `auth_id` int(10) unsigned NOT NULL, 
    `story_id` int(10) unsigned NOT NULL, 
    PRIMARY KEY (`fav_id`), 
    UNIQUE KEY `auth_id_2` (`auth_id`,`story_id`), 
    KEY `auth_id` (`auth_id`), 
    KEY `story_id` (`story_id`), 
    KEY `fav_id` (`fav_id`,`auth_id`,`story_id`) 
) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=1577985 ; 

CREATE TABLE IF NOT EXISTS `story` (
    `story_id` int(10) unsigned NOT NULL, 
    `story_title` varchar(255) NOT NULL, 
    `story_desc` text NOT NULL, 
    `story_authid` int(8) unsigned NOT NULL, 
    `story_authname` varchar(255) NOT NULL, 
    `story_fandom` varchar(255) NOT NULL, 
    `story_genre1` tinyint(2) unsigned NOT NULL, 
    `story_genre2` tinyint(2) unsigned NOT NULL, 
    `story_created` int(10) unsigned NOT NULL, 
    `story_updated` int(10) unsigned NOT NULL, 
    `story_reviews` smallint(5) unsigned NOT NULL, 
    `story_chapters` smallint(3) unsigned NOT NULL, 
    `story_rating` tinyint(2) unsigned NOT NULL, 
    `story_words` mediumint(7) unsigned NOT NULL, 
    `story_chars` varchar(255) NOT NULL, 
    UNIQUE KEY `story_id` (`story_id`), 
    KEY `story_authid` (`story_authid`), 
    KEY `story_fandom` (`story_fandom`), 
    KEY `story_authid_2` (`story_authid`,`story_fandom`), 
    KEY `story_id_2` (`story_id`,`story_authid`), 
    KEY `story_id_3` (`story_id`,`story_words`), 
    KEY `story_id_4` (`story_id`,`story_fandom`,`story_words`), 
    KEY `story_id_5` (`story_id`,`story_reviews`,`story_words`), 
    KEY `story_words` (`story_words`), 
    KEY `story_reviews` (`story_reviews`) 
) ENGINE=MyISAM DEFAULT CHARSET=utf8; 

現在我已經做了優化公平的位把查詢放到這裏。我在專用服務器上運行，但查詢仍需要5-7秒，這是不可接受的。我們正在查看關於收藏夾的約80萬條記錄和關於故事的400,000條記錄，而我現在在這一點上失去了尋找下一步改進的地方。

這似乎有點令人生畏，所以即使有人能指引我走向正確的方向，我也會很高興。

EXPLAIN與採樣輸入：

id select_type  table type possible_keys key  key_len  ref  rows Extra 
1 PRIMARY s1 ALL story_id,story_id_2,story_id_3,story_id_4,story_id... NULL NULL NULL 129429 Using where; Using temporary; Using filesort 
1 PRIMARY f1 ref story_id story_id 4 fanfic_jordanl_ffrecs.s1.story_id 2 Using where 
4 DEPENDENT SUBQUERY f4 eq_ref auth_id_2,auth_id,story_id auth_id_2 8 fanfic_jordanl_ffrecs.f1.auth_id,const 1 Using index 
3 DEPENDENT SUBQUERY f3 eq_ref auth_id_2,auth_id,story_id auth_id_2 8 fanfic_jordanl_ffrecs.f1.auth_id,const 1 Using index 
2 DEPENDENT SUBQUERY f2 eq_ref auth_id_2,auth_id,story_id auth_id_2 8 fanfic_jordanl_ffrecs.f1.auth_id,const 1 Using index 

Answer 1

試試這個：

SELECT f1.*, s1.*, COUNT(*) as `numauth` 
FROM `favorites` as `f1` 
INNER JOIN `story` as `s1` ON `f1`.`story_id` = `s1`.`story_id` 
INNER JOIN (
     SELECT auth_id 
     FROM favorites 
     WHERE story_id IN ('".addslashes($_REQUEST['storyid'])."', '".addslashes($_REQUEST['storyid2'])."', '".addslashes($_REQUEST['exclude'])."') 
     GROUP BY auth_id 
     HAVING Count(IF(story_id = '".addslashes($_REQUEST['exclude'])."', 1, NULL)) = 0 AND Count(*) = 2 
     ) fv ON f1.auth_id = fv.auth_id 
WHERE `f1`.`story_id` != '".addslashes($_REQUEST['storyid'])."' 
    AND `f1`.`story_id` != '".addslashes($_REQUEST['storyid2'])."' 
GROUP BY `f1`.`story_id` 
ORDER BY `numauth` DESC, `story_words` DESC 

既然你選擇*而不是由AUTH_ID分組，究竟什麼是你想怎麼辦？

--- UPDATE ，因爲你並不需要所有的故事喜歡的信息，這個查詢應該有更好的表現：

SELECT s.*, fv.cnt 
FROM story s 
    JOIN (
     SELECT fv.story_id, COUNT(*) cnt 
     FROM favorites fv 
      JOIN (
       SELECT auth_id 
       FROM favorites 
       WHERE story_id IN ('".addslashes($_REQUEST['storyid'])."', '".addslashes($_REQUEST['storyid2'])."', '".addslashes($_REQUEST['exclude'])."') 
       GROUP BY auth_id 
       HAVING Count(IF(story_id = '".addslashes($_REQUEST['exclude'])."', 1, NULL)) = 0 AND Count(*) = 2 
      ) ufv ON fv.auth_id = ufv.auth_id 
     WHERE story_id != '".addslashes($_REQUEST['storyid'])."' AND story_id != '".addslashes($_REQUEST['storyid2'])."' 
     GROUP BY fv.story_id 
     ORDER BY COUNT(*) DESC 
     LIMIT 25 
    ) fv ON s.story_id = fv.story_id 
ORDER BY fv.cnt DESC, `story_words` DESC