我正在尝试连接两个表,products
and products_markets
. While products
记录不足一百万条,product_markets
接近2000万条记录。数据已更改,因此架构创建表中可能存在一两个拼写错误:
CREATE TABLE `products_markets` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`product_id` int(10) unsigned NOT NULL,
`country_code_id` int(10) unsigned NOT NULL,
`created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`updated_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`id`),
UNIQUE KEY `unique_index` (`product_id`,`country_code_id`)
) ENGINE=InnoDB AUTO_INCREMENT=21052102 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
CREATE TABLE `products` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`manufacturer_id` int(10) unsigned NOT NULL,
`department_id` int(10) unsigned NOT NULL,
`code` varchar(100) COLLATE utf8mb4_unicode_ci NOT NULL,
`popularity` int(11) DEFAULT NULL,
`name` varchar(255) COLLATE utf8mb4_unicode_ci NOT NULL,
`value` bigint(20) unsigned NOT NULL,
`created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`updated_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`id`),
UNIQUE KEY `products_code_unique` (`code`),
KEY `products_department_id_foreign` (`department_id`),
KEY `products_manufacturer_id_foreign` (`manufacturer_id`),
CONSTRAINT `products_department_id_foreign`
FOREIGN KEY (`department_id`) REFERENCES `departments` (`id`),
CONSTRAINT `products_manufacturer_id_foreign`
FOREIGN KEY (`manufacturer_id`) REFERENCES `manufacturers` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=731563 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
我正在尝试返回特定国家/地区最受欢迎的产品的 50 条记录,但我遇到的时间大约为 50 秒,这似乎比预期要高。
我尝试了一些不同的查询但没有成功:
select `products_markets`.`product_id`
from products_markets
left join
( SELECT products.id, products.popularity
from products
) p ON p.id = products_markets.product_id
where products_markets.country_code_id = 121
order by `popularity` desc, `p`.`id` asc
limit 50
and
select `products`.*
from `products`
where products.id in (
SELECT product_id
from products_markets
where products_markets.country_code_id = 121
)
group by `products`.`name`, `products`.`manufacturer_id`
order by `popularity` desc, `products`.`id` asc
limit 50
这个查询的解释是:
id select_type table type possible_keys key key_len refs rows extra
1 PRIMARY products ALL PRIMARY NULL NULL NULL 623848 Using temporary; Using filesort
1 PRIMARY products_markets ref unique_index unique_index 4 main.products.id 14 Using where; Using index; FirstMatch(products)
我感兴趣的一个选择是将 products_markets 分成每个国家/地区的单独表,以减少查询。我尝试向服务器添加更多内存,但没有成功。任何人都可以识别出数据库设计/查询中存在明显错误的地方吗?
还有哪些其他选项可以使此查询缩短到当前约 50 秒的一小部分?