MySQL "OR MATCH"在多个表上挂起(非常慢)

Question

在学习了如何进行 MySQL 全文搜索之后，针对多个表的推荐解决方案是 OR MATCH，然后进行其他数据库调用。您可以在我下面的查询中看到这一点。

当我这样做时，它只是陷入“忙碌”状态，我无法访问 MySQL 数据库。

SELECT 
 a.`product_id`, a.`name`, a.`slug`, a.`description`, b.`list_price`, b.`price`, c.`image`, c.`swatch`, e.`name` AS industry, 
 MATCH( a.`name`, a.`sku`, a.`description` ) AGAINST ( '%s' IN BOOLEAN MODE )     AS relevance 
FROM 
 `products` AS a LEFT JOIN `website_products` AS b 
  ON (a.`product_id` = b.`product_id`) 
 LEFT JOIN ( SELECT `product_id`, `image`, `swatch` FROM `product_images` WHERE `sequence` = 0) AS c 
  ON (a.`product_id` = c.`product_id`) 
 LEFT JOIN `brands` AS d 
  ON (a.`brand_id` = d.`brand_id`) 
 INNER JOIN `industries` AS e ON (a.`industry_id` = e.`industry_id`) 
WHERE 
 b.`website_id` = %d
 AND b.`status` = %d
 AND b.`active` = %d 
 AND MATCH( a.`name`, a.`sku`, a.`description` ) AGAINST ( '%s' IN BOOLEAN MODE ) 
  OR MATCH ( d.`name` ) AGAINST ( '%s' IN BOOLEAN MODE )
GROUP BY a.`product_id` 
ORDER BY relevance DESC 
LIMIT 0, 9 

如有任何帮助，我们将不胜感激。

---

编辑

涉及到的表都是MyISAM，utf8_general_ci。

这是 EXPLAIN SELECT 语句:

id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY a ALL NULL NULL NULL NULL 16076 Using temporary; Using filesort
1 PRIMARY b ref product_id product_id 4 database.a.product_id 2  
1 PRIMARY e eq_ref PRIMARY PRIMARY 4 database.a.industry_id 1  
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 23261  
1 PRIMARY d eq_ref PRIMARY PRIMARY 4 database.a.brand_id 1 Using where
2 DERIVED product_images ALL NULL NULL NULL NULL 25933 Using where

我不知道如何使它看起来更整洁——对此感到抱歉

---

更新

它在 196 秒后返回查询(我认为是正确的)。没有多个表的查询大约需要 0.56 秒(我知道这真的很慢，我们计划很快改用 solr 或 sphinx)，但是 196 秒？？

如果我们可以在品牌名称 ( d.name ) 中为相关性添加一个数字，那也行得通

Answer 1

我发现有 2 个问题大大减慢了我的查询速度并修复了它们。

要回答第一个问题，需要在整个“MATCH AGAINST OR MATCH AGAINST”周围加上括号:

WHERE 
    b.`website_id` = %d
    AND b.`status` = %d
    AND b.`active` = %d 
    AND ( 
        MATCH( a.`name`, a.`sku`, a.`description` ) AGAINST ( '%s' IN BOOLEAN MODE ) 
        OR MATCH ( d.`name` ) AGAINST ( '%s' IN BOOLEAN MODE )
    )

我不明白如何使用EXPLAIN SELECT，但它帮了我不少忙，谢谢!这将第一个数字 16076 行减少到 143。然后我注意到另外两个有超过 23 和 25000 行。这是这一行的原因:

LEFT JOIN ( SELECT `product_id`, `image`, `swatch` FROM `product_images` WHERE `sequence` = 0) AS c 
    ON (a.`product_id` = c.`product_id`)

我最初这样做是有原因的，后来改变了。当我更改它时，我没有意识到我可以进行正常的 LEFT JOIN:

LEFT JOIN `product_images` AS c 
    ON (a.`product_id` = c.`product_id`)

---

这使我的最终查询变成这样:(而且从 196 秒到 0.0084 秒左右快得多)

SELECT 
    a.`product_id`, a.`name`, a.`slug`, a.`description`, b.`list_price`, b.`price`, 
    c.`image`, c.`swatch`, e.`name` AS industry, 
    MATCH( a.`name`, a.`sku`, a.`description` ) AGAINST ( '%s' IN BOOLEAN MODE ) AS relevance 
FROM 
    `products` AS a LEFT JOIN `website_products` AS b 
        ON (a.`product_id` = b.`product_id`) 
    LEFT JOIN `product_images` AS c 
        ON (a.`product_id` = c.`product_id`) 
    LEFT JOIN `brands` AS d 
        ON (a.`brand_id` = d.`brand_id`) 
    INNER JOIN `industries` AS e 
        ON (a.`industry_id` = e.`industry_id`) 
WHERE 
    b.`website_id` = %d
    AND b.`status` = %d
    AND b.`active` = %d
    AND c.`sequence` = %d
    AND ( 
        MATCH( a.`name`, a.`sku`, a.`description` ) AGAINST ( '%s' IN BOOLEAN MODE ) 
        OR MATCH( d.`name` ) AGAINST( '%s' IN BOOLEAN MODE ) 
    )
GROUP BY a.`product_id` 
ORDER BY relevance DESC 
LIMIT 0, 9

哦，甚至在我对多个表进行全文搜索之前，它也需要大约 1/2 秒。这是很大的改进。