Question

这是我的查询的缩写：

SELECT product.* FROM product_list product
LEFT JOIN language_item language ON (product.title=language.languageVariable)
WHERE language.languageID = 1
ORDER BY language.languageValue ASC

当我使用它时，查询有3秒钟。当我通过查询删除订单时有0.3秒。你能推荐一个改变来加速吗？

product.title和language.languageVariable是一个语言变量，如global.product.title1，languageValue是标题，如汽车，玩偶或其他东西。

CREATE TABLE `language_item` (
  `languageItemID` int(10) UNSIGNED NOT NULL,
  `languageID` int(10) UNSIGNED NOT NULL DEFAULT '0',
  `languageVariable` varchar(255) NOT NULL DEFAULT '',
  `languageValue` mediumtext NOT NULL,
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
ALTER TABLE `language_item`
  ADD PRIMARY KEY (`languageItemID`),
  ADD UNIQUE KEY `languageVariable` (`languageVariable`,`languageID`),
  ADD KEY `languageValue` (`languageValue`(300));

id | select_type | table    | partitions | type | possible_keys                              | key              | key_len | ref              | rows | filtered | Extra 
 1 | SIMPLE      | product  | NULL       | ALL  | PRIMARY,inactive,archive,productCategoryID | NULL             | NULL    | NULL             | 1475 |    88.27 | Using where; Using temporary; Using filesort 
 1 | SIMPLE      | language | NULL       | ref  | languageVariable                           | languageVariable | 767     | db.product.title |  136 |     1.00 | Using index condition

Answer 1

试试这个：

SELECT d.* from (
  SELECT product.*, language.languageValue AS lv
  FROM product_list product
  JOIN language_item language ON (product.title=language.languageVariable)
  WHERE language.languageID = 1
) as d
ORDER BY d.lv ASC

Answer 2

以下是language_item的结构，索引为：

CREATE TABLE `language_item` (
  `languageItemID` int(10) UNSIGNED NOT NULL,
  `languageID` int(10) UNSIGNED NOT NULL DEFAULT '0',
  `languageVariable` varchar(255) NOT NULL DEFAULT '',
  `languageValue` mediumtext NOT NULL,
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
ALTER TABLE `language_item`
  ADD PRIMARY KEY (`languageItemID`),
  ADD UNIQUE KEY `languageVariable` (`languageVariable`,`languageID`),
  ADD KEY `languageValue` (`languageValue`(300));

解释：

id | select_type |表|分区|类型| possible_keys |关键| key_len | ref |行|过滤|额外1 |简单|产品| NULL | 所有| PRIMARY，非活动，归档，productCategoryID | NULL | NULL |空值 | 1475 | 88.27 |用在哪里;使用临时;使用filesort 1 | 简单|语言| NULL | ref | languageVariable | languageVariable | 767 | db.product.title | 136 | 1.00 |使用索引条件

加速MySQL查询

2 个答案: