请帮我优化mysql搜索查询

Question

我在 MySql (5.1) InnoDB 中有一个查询，它在包含部分的表中进行搜索。包含部件的表包含大约 500 000 行。该搜索还连接另外两个表 tblcategory 和 tblheadcategory。我有很多用户使用这个查询，这使得我的服务器几乎因负载过重而崩溃。

我知道一个好的方法是使用全文搜索，我希望我们可以改变它以在将来使用它。但由于 InnoDB 不可能做到这一点，我需要一个“快速”优化来让它暂时运行。我应该如何优化它并设置索引和其他东西以使这个查询尽可能好地运行？

这是查询：

SELECT tblpart.partid,tblpart.title,tblcategory.category,tblheadcategory.headcategory

FROM tblpart

INNER JOIN tblcategory ON tblpart.categoryid = tblcategory.categoryid
INNER JOIN tblheadcategory ON tblcategory.headcategoryid = tblheadcategory.headcategoryid

WHERE (tblpart.title LIKE '%bmw%' OR tblpart.description LIKE '%bmw%' OR tblpart.brand LIKE '%bmw%')

ORDER BY

tblpart.title='bmw' DESC,
tblcategory.category LIKE '%bmw%' DESC

LIMIT 50;

表：

CREATE TABLE `tblpart` (
    `partid` int(10) NOT NULL auto_increment,
    `userid` int(11) default '1',
    `categoryid` int(10) default '1',
    `title` varchar(100) default NULL,
    `brand` varchar(100) default NULL,
    `description` varchar(100) default NULL,
    PRIMARY KEY  (`partid`),
    KEY `userid` (`userid`),
    KEY `title` (`title`)
) ENGINE=InnoDB AUTO_INCREMENT=534007 DEFAULT CHARSET=utf8;

CREATE TABLE `tblcategory` (
    `categoryid` int(10) NOT NULL auto_increment,
    `category` varchar(255) default NULL,
    `headcategoryid` int(10) default NULL,
      PRIMARY KEY  (`categoryid`)
) ENGINE=InnoDB AUTO_INCREMENT=1261 DEFAULT CHARSET=utf8;

CREATE TABLE `tblheadcategory` (
    `headcategoryid` int(10) NOT NULL auto_increment,
    `headcategory` varchar(255) default NULL,
    PRIMARY KEY  (`headcategoryid`)
) ENGINE=InnoDB AUTO_INCREMENT=21 DEFAULT CHARSET=utf8;

EXPLAIN 给出以下内容： （抱歉，我不知道如何正确格式化它）

id   select_type   table            type    possible_keys   key      key_len  ref                         rows        extra
1    SIMPLE        tblpart          ALL     NULL            NULL     NULL     NULL                        522905      Using where; Using temporary; Using filesort
1    SIMPLE        tblcategory      eq_ref  PRIMARY         PRIMARY  4        tblpart.categoryid          1
1    SIMPLE        tblheadcategory  eq_ref  PRIMARY         PRIMARY  4        tblcategory.headcategoryid  1 

---

UPDATE

根据建议，我尝试了全文解决方案：

新的 MyISAM 表：

CREATE TABLE `tblpart_search` (
    `partid` int(11) NOT NULL AUTO_INCREMENT,
    `title` varchar(100) NOT NULL,
    `brand` varchar(100) DEFAULT NULL,
    `description` varchar(100) DEFAULT NULL,
    PRIMARY KEY (`partid`),
    FULLTEXT KEY `all` (`title`,`brand`,`description`)
) ENGINE=MyISAM AUTO_INCREMENT=359596 DEFAULT CHARSET=utf8;

触发器：

DELIMITER ;;
CREATE TRIGGER `tblpart_insert_trigger` AFTER INSERT ON `tblpart` 
FOR EACH ROW INSERT INTO tblpart_search VALUES(NEW.partid,NEW.title,NEW.brand,NEW.description);;
DELIMITER ;

DELIMITER ;;
CREATE TRIGGER `tblpart_update_trigger` AFTER UPDATE ON `tblpart` 
FOR EACH ROW UPDATE tblpart_search SET tblpart_search.title=NEW.title,tblpart_search.brand=NEW.brand,tblpart_search.description=NEW.description WHERE tblpart_search.partid=NEW.partid;;
DELIMITER ;

DELIMITER ;;
CREATE TRIGGER `tblpart_delete_trigger` AFTER DELETE ON `tblpart` 
FOR EACH ROW DELETE FROM tblpart_search WHERE tblpart_search.partid=OLD.partid;;
DELIMITER ;

新查询：

SELECT tblpart.partid,tblpart.title,tblcategory.category,tblheadcategory.headcategory

FROM tblpart_search
INNER JOIN tblpart ON tblpart_search.partid = tblpart.partid
INNER JOIN tblcategory ON tblpart.categoryid = tblcategory.categoryid
INNER JOIN tblheadcategory ON tblcategory.headcategoryid = tblheadcategory.headcategoryid

WHERE MATCH (tblpart_search.title, tblpart_search.brand, tblpart_search.description) AGAINST ('bmw,car')
LIMIT 50;

Answer 1

您无法真正优化带有前导通配符的查询（即使使用 FULLTEXT 搜索）。

您在这里唯一能做的就是将查询分成三部分（在客户端）：

SELECT  tblpart.partid,tblpart.title,tblcategory.category,tblheadcategory.headcategory
FROM    tblpart
INNER JOIN
        tblcategory
ON      tblpart.categoryid = tblcategory.categoryid
INNER JOIN
        tblheadcategory
ON      tblcategory.headcategoryid = tblheadcategory.headcategoryid
WHERE   tblpart.title = 'bmw'
ORDER BY
        tblcategory.category LIKE '%bmw%' DESC
LIMIT 50

SELECT  tblpart.partid,tblpart.title,tblcategory.category,tblheadcategory.headcategory
FROM    tblpart
INNER JOIN
        tblcategory
ON      tblpart.categoryid = tblcategory.categoryid
INNER JOIN
        tblheadcategory
ON      tblcategory.headcategoryid = tblheadcategory.headcategoryid
WHERE   tblpart.title <> 'bmw'
        AND  (tblpart.title LIKE '%bmw%' OR tblpart.description LIKE '%bmw%' OR tblpart.brand LIKE '%bmw%')
        AND tblcategory.category LIKE '%bmw%'
LIMIT N

SELECT  tblpart.partid,tblpart.title,tblcategory.category,tblheadcategory.headcategory
FROM    tblpart
INNER JOIN
        tblcategory
ON      tblpart.categoryid = tblcategory.categoryid
INNER JOIN
        tblheadcategory
ON      tblcategory.headcategoryid = tblheadcategory.headcategoryid
WHERE   tblpart.title <> 'bmw'
        AND  (tblpart.title LIKE '%bmw%' OR tblpart.description LIKE '%bmw%' OR tblpart.brand LIKE '%bmw%')
        AND tblcategory.category NOT LIKE '%bmw%'
LIMIT N

并将最后一个查询中的 N 替换为 50 - 记录，其中 Records 是先前查询返回的记录数。

第一个查询可以通过 title 上的索引来提供。

更新：

FULLTEXT 搜索可以这样实现：

CREATE TABLE `tblpart_search` (
    `partid` int(11) NOT NULL AUTO_INCREMENT,
    `title` varchar(100) NOT NULL,
    `brand` varchar(100) DEFAULT NULL,
    `description` varchar(100) DEFAULT NULL,
    PRIMARY KEY (`partid`),
    FULLTEXT KEY `all` (`title`,`brand`,`description`)
) ENGINE=MyISAM AUTO_INCREMENT=359596 DEFAULT CHARSET=utf8;

触发器：

DELIMITER ;;
CREATE TRIGGER `tblpart_insert_trigger` AFTER INSERT ON `tblpart` 
FOR EACH ROW INSERT INTO tblpart_search VALUES(NEW.partid,NEW.title,NEW.brand,NEW.description);;
DELIMITER ;

DELIMITER ;;
CREATE TRIGGER `tblpart_update_trigger` AFTER UPDATE ON `tblpart` 
FOR EACH ROW UPDATE tblpart_search SET tblpart_search.title=NEW.title,tblpart_search.brand=NEW.brand,tblpart_search.description=NEW.description WHERE tblpart_search.partid=NEW.partid;;
DELIMITER ;

DELIMITER ;;
CREATE TRIGGER `tblpart_delete_trigger` AFTER DELETE ON `tblpart` 
FOR EACH ROW DELETE FROM tblpart_search WHERE tblpart_search.partid=OLD.partid;;
DELIMITER ;

新查询：

SELECT tblpart.partid,tblpart.title,tblcategory.category,tblheadcategory.headcategory

FROM tblpart_search
INNER JOIN tblpart ON tblpart_search.partid = tblpart.partid
INNER JOIN tblcategory ON tblpart.categoryid = tblcategory.categoryid
INNER JOIN tblheadcategory ON tblcategory.headcategoryid = tblheadcategory.headcategoryid

WHERE MATCH (tblpart_search.title, tblpart_search.brand, tblpart_search.description) AGAINST ('+bmw +car' IN BOOLEAN MODE)
LIMIT 50;

将 ft_min_word_len 设置为 3 或更少，以便它可以索引 3 字符单词，例如 'BMW' 和 'CAR'。

Answer 2

对 where 子句中使用的字段建立索引。我不确定是否有“tblpart.title='bmw' DESC, tblcategory.category LIKE '%bmw%' DESC”，因为我只做了“索引 where 子句中使用的字段”之类的事情。我不确定tblpart.title DESC，tblcategory.category DESC"

Answer 3

1. 我认为代码
   tblpart.title='bmw' DESC 应该是
   更改为 tblpart.title LIKE
'%bmw%' DESC
2. 创建一个新表，该表将用作文本搜索的索引，您可以在其中存储用户输入的搜索词以及与 tblpart.title< 相关的常用搜索词/code> 和 partid。现在，每当用户点击搜索时，您都会首先搜索此表，如果搜索词与该 partid 的查询匹配，则速度要快得多。