如何缩短 Laravel 查询生成器生成的 SQL 查询的执行时间
How to improve execution time of a Laravel Query Builder generated SQL query
我有三个 table 与此查询有关
CREATE TABLE `tags` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`latName` varchar(191) NOT NULL,
`araName` varchar(191) NOT NULL,
`active` tinyint(1) NOT NULL DEFAULT 0,
`img_name` varchar(191) DEFAULT NULL,
`icon` varchar(191) DEFAULT NULL,
`rgba_color` varchar(191) DEFAULT NULL,
`color` varchar(191) DEFAULT NULL,
`overlay` varchar(191) DEFAULT NULL,
`position` int(11) NOT NULL,
`mdi_icon` varchar(191) NOT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `tags_latname_unique` (`latName`),
UNIQUE KEY `tags_araname_unique` (`araName`)
) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8mb3
CREATE TABLE `newspapers` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`latName` varchar(191) NOT NULL,
`araName` varchar(191) NOT NULL,
`img_name` varchar(191) DEFAULT NULL,
`active` tinyint(1) NOT NULL DEFAULT 0,
PRIMARY KEY (`id`),
UNIQUE KEY `newspapers_latname_unique` (`latName`),
UNIQUE KEY `newspapers_araname_unique` (`araName`)
) ENGINE=InnoDB AUTO_INCREMENT=21 DEFAULT CHARSET=utf8mb3
CREATE TABLE `articles` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`newspaper_id` bigint(20) unsigned NOT NULL,
`tag_id` bigint(20) unsigned NOT NULL,
`seen` int(10) unsigned NOT NULL,
`link` varchar(1000) NOT NULL,
`title` varchar(191) NOT NULL,
`img_name` varchar(191) NOT NULL,
`date` datetime NOT NULL,
`paragraph` text NOT NULL,
`read_time` int(11) DEFAULT NULL,
`created_at` timestamp NULL DEFAULT NULL,
`updated_at` timestamp NULL DEFAULT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `articles_link_unique` (`link`),
UNIQUE KEY `articles_img_name_unique` (`img_name`),
KEY `articles_newspaper_id_foreign` (`newspaper_id`),
KEY `articles_tag_id_foreign` (`tag_id`),
CONSTRAINT `articles_newspaper_id_foreign` FOREIGN KEY (`newspaper_id`) REFERENCES `newspapers` (`id`),
CONSTRAINT `articles_tag_id_foreign` FOREIGN KEY (`tag_id`) REFERENCES `tags` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=47421 DEFAULT CHARSET=utf8mb3
基本上，我想加载最新的 5 篇具有活跃报纸和活跃标签的文章（按日期排序）。
目前文章 table 包含大约 40k 个条目。
这是由 Laravel 的查询生成器生成的查询
SELECT `articles`.*
FROM `articles`
INNER JOIN `tags` ON `tags`.`id` = `articles`.`tag_id`
AND `tags`.`active` = 1
INNER JOIN `newspapers` ON `newspapers`.`id` = `articles`.`newspaper_id`
AND `newspapers`.`active` = 1
ORDER BY `date` DESC
LIMIT 5;
查询 运行 需要 Mysql 大约 6 秒，当我删除 ORDER BY 子句时，查询变得非常快（0.001 秒）。
查询说明如下：
+------+-------------+------------+--------+-------------------------------------------------------+-------------------------------+---------+------------------------+------+----------------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+------+-------------+------------+--------+-------------------------------------------------------+-------------------------------+---------+------------------------+------+----------------------------------------------+
| 1 | SIMPLE | newspapers | ALL | PRIMARY | NULL | NULL | NULL | 18 | Using where; Using temporary; Using filesort |
| 1 | SIMPLE | articles | ref | articles_newspaper_id_foreign,articles_tag_id_foreign | articles_newspaper_id_foreign | 8 | mouhim.newspapers.id | 1127 | |
| 1 | SIMPLE | tags | eq_ref | PRIMARY | PRIMARY | 8 | mouhim.articles.tag_id | 1 | Using where |
+------+-------------+------------+--------+-------------------------------------------------------+-------------------------------+---------+------------------------+------+----------------------------------------------+
我尝试在日期属性上创建索引，但没有帮助。
为方便起见，这就是我为此查询使用查询生成器的方式：
Article::select("articles.*")
->join("tags", function ($join) {
$join->on("tags.id", "articles.tag_id")
->where("tags.active", 1);
})
->join("newspapers", function ($join) {
$join->on("newspapers.id", "articles.newspaper_id")
->where("newspapers.active", 1);
})
->orderBy("date", "desc")
->paginate(5)
起初，我使用的是 Eloquent (whereHas)，但 Eloquent 使用 (where exists) 生成非优化查询，所以我不得不采用连接方式。
我可以做些什么来缩短这个查询的执行时间？
SHOW INDEXES FROM articles;
的结果
+----------+------------+-------------------------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | Ignored |
+----------+------------+-------------------------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+
| articles | 0 | PRIMARY | 1 | id | A | 36072 | NULL | NULL | | BTREE | | | NO |
| articles | 0 | articles_link_unique | 1 | link | A | 36072 | NULL | NULL | | BTREE | | | NO |
| articles | 0 | articles_img_name_unique | 1 | img_name | A | 36072 | NULL | NULL | | BTREE | | | NO |
| articles | 1 | articles_newspaper_id_foreign | 1 | newspaper_id | A | 32 | NULL | NULL | | BTREE | | | NO |
| articles | 1 | articles_tag_id_foreign | 1 | tag_id | A | 12 | NULL | NULL | | BTREE | | | NO |
| articles | 1 | data | 1 | date | A | 36072 | NULL | NULL | | BTREE | | | NO |
+----------+------------+-------------------------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+
此查询由 Rick James 建议作为解决方案
SELECT `articles`.*
FROM `articles`
WHERE EXISTS ( SELECT 1 FROM tags WHERE id = `articles`.`tag_id` and active = 1)
AND EXISTS ( SELECT 1 FROM newspapers WHERE id = `articles`.`newspaper_id` and active = 1)
ORDER BY `date` DESC
LIMIT 5;
运行 EXPLAIN 对此查询产生以下结果
+------+-------------+------------+--------+-------------------------------------------------------+-------------------------------+---------+------------------------+------+----------------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+------+-------------+------------+--------+-------------------------------------------------------+-------------------------------+---------+------------------------+------+----------------------------------------------+
| 1 | PRIMARY | newspapers | ALL | PRIMARY | NULL | NULL | NULL | 18 | Using where; Using temporary; Using filesort |
| 1 | PRIMARY | articles | ref | articles_newspaper_id_foreign,articles_tag_id_foreign | articles_newspaper_id_foreign | 8 | mouhim.newspapers.id | 1127 | |
| 1 | PRIMARY | tags | eq_ref | PRIMARY | PRIMARY | 8 | mouhim.articles.tag_id | 1 | Using where |
+------+-------------+------------+--------+-------------------------------------------------------+-------------------------------+---------+------------------------+------+----------------------------------------------+
我不确定这两个查询是否应该相同，但事实并非如此。
无论如何，对于第二个查询，我认为这应该更好
Article::leftJoin('tags', 'articles.tag_id', '=', 'tags.id)
->where('tags.latName', $tag)
->orderBy("articles.date", "desc")
->select(['articles.*'])
->paginate(5);
问题可能在于，您在 whereIn 中创建的子查询正在减慢它的速度，而 whereIn 本身也可能会减慢您的查询速度。这可以通过使用 join 和 where 来缓解。
关于第一个查询，你能展示一下你是如何为日期建立索引的吗？ :)
假设你不想复制，改成这个；它可能会快得多：
SELECT `articles`.*
FROM `articles`
WHERE EXISTS ( SELECT 1 FROM tags
WHERE id = `articles`.`tag_id` )
AND EXISTS ( SELECT 1 FROM newspapers
WHERE id = `articles`.`newspaper_id` )
ORDER BY `date` DESC
LIMIT 5;
此外，在 articles 上有此索引：
INDEX(date)
（这是 罕见的 用例 starting 索引，其列将在 'range' 中使用。 )
（抱歉，我不会说 'Laravel'；也许其他人可以帮助解决这部分问题。）
PS。在 table 上有 3 个 UNIQUE 键是非常不寻常的。它通常表示架构设计存在问题。
each article has one and only one Tag associated with it
多篇文章可以有相同的Tag吗？
when I remove the ORDER BY clause, the query becomes very fast (0.001sec).
那是因为您可以轻松地 return 得到任何 5 行。显然 ORDER BY 是要求的一部分。 “使用临时文件；使用文件排序”说至少有一种排序。它实际上是一种“文件”排序——因为 SELECT * 包含一个 TEXT 列。 （有一种技术可以避免“文件”，但我认为这里不需要。）
我有三个 table 与此查询有关
CREATE TABLE `tags` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`latName` varchar(191) NOT NULL,
`araName` varchar(191) NOT NULL,
`active` tinyint(1) NOT NULL DEFAULT 0,
`img_name` varchar(191) DEFAULT NULL,
`icon` varchar(191) DEFAULT NULL,
`rgba_color` varchar(191) DEFAULT NULL,
`color` varchar(191) DEFAULT NULL,
`overlay` varchar(191) DEFAULT NULL,
`position` int(11) NOT NULL,
`mdi_icon` varchar(191) NOT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `tags_latname_unique` (`latName`),
UNIQUE KEY `tags_araname_unique` (`araName`)
) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8mb3
CREATE TABLE `newspapers` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`latName` varchar(191) NOT NULL,
`araName` varchar(191) NOT NULL,
`img_name` varchar(191) DEFAULT NULL,
`active` tinyint(1) NOT NULL DEFAULT 0,
PRIMARY KEY (`id`),
UNIQUE KEY `newspapers_latname_unique` (`latName`),
UNIQUE KEY `newspapers_araname_unique` (`araName`)
) ENGINE=InnoDB AUTO_INCREMENT=21 DEFAULT CHARSET=utf8mb3
CREATE TABLE `articles` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`newspaper_id` bigint(20) unsigned NOT NULL,
`tag_id` bigint(20) unsigned NOT NULL,
`seen` int(10) unsigned NOT NULL,
`link` varchar(1000) NOT NULL,
`title` varchar(191) NOT NULL,
`img_name` varchar(191) NOT NULL,
`date` datetime NOT NULL,
`paragraph` text NOT NULL,
`read_time` int(11) DEFAULT NULL,
`created_at` timestamp NULL DEFAULT NULL,
`updated_at` timestamp NULL DEFAULT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `articles_link_unique` (`link`),
UNIQUE KEY `articles_img_name_unique` (`img_name`),
KEY `articles_newspaper_id_foreign` (`newspaper_id`),
KEY `articles_tag_id_foreign` (`tag_id`),
CONSTRAINT `articles_newspaper_id_foreign` FOREIGN KEY (`newspaper_id`) REFERENCES `newspapers` (`id`),
CONSTRAINT `articles_tag_id_foreign` FOREIGN KEY (`tag_id`) REFERENCES `tags` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=47421 DEFAULT CHARSET=utf8mb3
基本上，我想加载最新的 5 篇具有活跃报纸和活跃标签的文章（按日期排序）。
目前文章 table 包含大约 40k 个条目。
这是由 Laravel 的查询生成器生成的查询
SELECT `articles`.*
FROM `articles`
INNER JOIN `tags` ON `tags`.`id` = `articles`.`tag_id`
AND `tags`.`active` = 1
INNER JOIN `newspapers` ON `newspapers`.`id` = `articles`.`newspaper_id`
AND `newspapers`.`active` = 1
ORDER BY `date` DESC
LIMIT 5;
查询 运行 需要 Mysql 大约 6 秒，当我删除 ORDER BY 子句时，查询变得非常快（0.001 秒）。
查询说明如下：
+------+-------------+------------+--------+-------------------------------------------------------+-------------------------------+---------+------------------------+------+----------------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+------+-------------+------------+--------+-------------------------------------------------------+-------------------------------+---------+------------------------+------+----------------------------------------------+
| 1 | SIMPLE | newspapers | ALL | PRIMARY | NULL | NULL | NULL | 18 | Using where; Using temporary; Using filesort |
| 1 | SIMPLE | articles | ref | articles_newspaper_id_foreign,articles_tag_id_foreign | articles_newspaper_id_foreign | 8 | mouhim.newspapers.id | 1127 | |
| 1 | SIMPLE | tags | eq_ref | PRIMARY | PRIMARY | 8 | mouhim.articles.tag_id | 1 | Using where |
+------+-------------+------------+--------+-------------------------------------------------------+-------------------------------+---------+------------------------+------+----------------------------------------------+
我尝试在日期属性上创建索引，但没有帮助。
为方便起见，这就是我为此查询使用查询生成器的方式：
Article::select("articles.*")
->join("tags", function ($join) {
$join->on("tags.id", "articles.tag_id")
->where("tags.active", 1);
})
->join("newspapers", function ($join) {
$join->on("newspapers.id", "articles.newspaper_id")
->where("newspapers.active", 1);
})
->orderBy("date", "desc")
->paginate(5)
起初，我使用的是 Eloquent (whereHas)，但 Eloquent 使用 (where exists) 生成非优化查询，所以我不得不采用连接方式。
我可以做些什么来缩短这个查询的执行时间？
SHOW INDEXES FROM articles;
+----------+------------+-------------------------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | Ignored |
+----------+------------+-------------------------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+
| articles | 0 | PRIMARY | 1 | id | A | 36072 | NULL | NULL | | BTREE | | | NO |
| articles | 0 | articles_link_unique | 1 | link | A | 36072 | NULL | NULL | | BTREE | | | NO |
| articles | 0 | articles_img_name_unique | 1 | img_name | A | 36072 | NULL | NULL | | BTREE | | | NO |
| articles | 1 | articles_newspaper_id_foreign | 1 | newspaper_id | A | 32 | NULL | NULL | | BTREE | | | NO |
| articles | 1 | articles_tag_id_foreign | 1 | tag_id | A | 12 | NULL | NULL | | BTREE | | | NO |
| articles | 1 | data | 1 | date | A | 36072 | NULL | NULL | | BTREE | | | NO |
+----------+------------+-------------------------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+
此查询由 Rick James 建议作为解决方案
SELECT `articles`.*
FROM `articles`
WHERE EXISTS ( SELECT 1 FROM tags WHERE id = `articles`.`tag_id` and active = 1)
AND EXISTS ( SELECT 1 FROM newspapers WHERE id = `articles`.`newspaper_id` and active = 1)
ORDER BY `date` DESC
LIMIT 5;
运行 EXPLAIN 对此查询产生以下结果
+------+-------------+------------+--------+-------------------------------------------------------+-------------------------------+---------+------------------------+------+----------------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+------+-------------+------------+--------+-------------------------------------------------------+-------------------------------+---------+------------------------+------+----------------------------------------------+
| 1 | PRIMARY | newspapers | ALL | PRIMARY | NULL | NULL | NULL | 18 | Using where; Using temporary; Using filesort |
| 1 | PRIMARY | articles | ref | articles_newspaper_id_foreign,articles_tag_id_foreign | articles_newspaper_id_foreign | 8 | mouhim.newspapers.id | 1127 | |
| 1 | PRIMARY | tags | eq_ref | PRIMARY | PRIMARY | 8 | mouhim.articles.tag_id | 1 | Using where |
+------+-------------+------------+--------+-------------------------------------------------------+-------------------------------+---------+------------------------+------+----------------------------------------------+
我不确定这两个查询是否应该相同，但事实并非如此。
无论如何，对于第二个查询，我认为这应该更好
Article::leftJoin('tags', 'articles.tag_id', '=', 'tags.id)
->where('tags.latName', $tag)
->orderBy("articles.date", "desc")
->select(['articles.*'])
->paginate(5);
问题可能在于，您在 whereIn 中创建的子查询正在减慢它的速度，而 whereIn 本身也可能会减慢您的查询速度。这可以通过使用 join 和 where 来缓解。
关于第一个查询，你能展示一下你是如何为日期建立索引的吗？ :)
假设你不想复制，改成这个；它可能会快得多：
SELECT `articles`.*
FROM `articles`
WHERE EXISTS ( SELECT 1 FROM tags
WHERE id = `articles`.`tag_id` )
AND EXISTS ( SELECT 1 FROM newspapers
WHERE id = `articles`.`newspaper_id` )
ORDER BY `date` DESC
LIMIT 5;
此外，在 articles 上有此索引：
INDEX(date)
（这是 罕见的 用例 starting 索引，其列将在 'range' 中使用。 )
（抱歉，我不会说 'Laravel'；也许其他人可以帮助解决这部分问题。）
PS。在 table 上有 3 个 UNIQUE 键是非常不寻常的。它通常表示架构设计存在问题。
each article has one and only one Tag associated with it
多篇文章可以有相同的Tag吗？
when I remove the ORDER BY clause, the query becomes very fast (0.001sec).
那是因为您可以轻松地 return 得到任何 5 行。显然 ORDER BY 是要求的一部分。 “使用临时文件；使用文件排序”说至少有一种排序。它实际上是一种“文件”排序——因为 SELECT * 包含一个 TEXT 列。 （有一种技术可以避免“文件”，但我认为这里不需要。）