Question

下面的查询，使用CakePHP的i18n表，需要大约1000毫秒才能运行。我的i18n表很大 - 它有大约600,000行。根据Cake架构，我在此表上有默认索引。

如何加快这样的查询速度？我在可能的情况下缓存它们，但是当需要清除缓存时，这些查询会被运行，并且它们会显着降低性能。

SELECT `Category`.`id`, `Category`.`slug`, `Category`.`name`, `Category`.`description`, `Category`.`head_title`, `Category`.`display_title`, `Category`.`category_count`, `Category`.`product_count`, `Category`.`parent_id`, `Category`.`lft`, `Category`.`rght`, `Category`.`sort_order`, `Category`.`created`, `Category`.`modified`, `Category`.`image_processed`, ((rght - lft) = 1) AS `Category__is_child`, (`I18n__name`.`content`) AS `Category__i18n_name`, (`I18n__description`.`content`) AS `Category__i18n_description`, (`I18n__slug`.`content`) AS `Category__i18n_slug`, (`I18n__head_title`.`content`) AS `Category__i18n_head_title`, (`I18n__meta_description`.`content`) AS `Category__i18n_meta_description`, (`I18n__heading_title`.`content`) AS `Category__i18n_heading_title` FROM `fracmerl_dev`.`categories` AS `Category`
    INNER JOIN `fracmerl_dev`.`i18n` AS `I18n__name` 
        ON (`Category`.`id` = `I18n__name`.`foreign_key`
        AND `I18n__name`.`model` = 'Category' 
        AND `I18n__name`.`field` = 'name'
        AND `I18n__name`.`locale` = 'eng')
    INNER JOIN `fracmerl_dev`.`i18n` AS `I18n__description`
        ON (`Category`.`id` = `I18n__description`.`foreign_key`
        AND `I18n__description`.`model` = 'Category'
        AND `I18n__description`.`field` = 'description' 
        AND `I18n__description`.`locale` = 'eng')
    INNER JOIN `fracmerl_dev`.`i18n` AS `I18n__slug`
        ON (`Category`.`id` = `I18n__slug`.`foreign_key`
        AND `I18n__slug`.`model` = 'Category'
        AND `I18n__slug`.`field` = 'slug'
        AND `I18n__slug`.`locale` = 'eng')
    INNER JOIN `fracmerl_dev`.`i18n` AS `I18n__head_title`
        ON (`Category`.`id` = `I18n__head_title`.`foreign_key`
        AND `I18n__head_title`.`model` = 'Category'
        AND `I18n__head_title`.`field` = 'head_title'
        AND `I18n__head_title`.`locale` = 'eng')
    INNER JOIN `fracmerl_dev`.`i18n` AS `I18n__meta_description`
        ON (`Category`.`id` = `I18n__meta_description`.`foreign_key`
        AND `I18n__meta_description`.`model` = 'Category'
        AND `I18n__meta_description`.`field` = 'meta_description'
        AND `I18n__meta_description`.`locale` = 'eng')
    INNER JOIN `fracmerl_dev`.`i18n` AS `I18n__heading_title`
        ON (`Category`.`id` = `I18n__heading_title`.`foreign_key`
        AND `I18n__heading_title`.`model` = 'Category'
        AND `I18n__heading_title`.`field` = 'heading_title'
        AND `I18n__heading_title`.`locale` = 'eng')
WHERE `I18n__slug`.`content` = 'category-slug'
ORDER BY `Category`.`sort_order` ASC, `Category`.`name` ASC
LIMIT 1

编辑 - 索引，SHOW INDEX FROM i18n

的结果

i18n    0   PRIMARY 1   id  A   598455  NULL    NULL        BTREE
i18n    1   locale  1   locale  A   5   NULL    NULL        BTREE
i18n    1   model   1   model   A   3   NULL    NULL        BTREE
i18n    1   row_id  1   foreign_key A   18701   NULL  NULL  BTREE
i18n    1   field   1   field   A   9   NULL    NULL        BTREE

Answer 1

如果您的i18n表很大，请尝试将其拆分并使用Multiple Translation Tables。

Answer 2

尝试将条件从WHERE转移到ON连接表。通常，应该没有区别，但如果查询优化器工作错误或无效，那么早期条件会减少行数，从而提高性能。

一些链接：

忘了说，原因，我的意思是你可以

`I18n__slug`.`content` = 'category-slug'

转到ON声明。

类似的东西：

INNER JOIN `fracmerl_dev`.`i18n` AS `I18n__slug`
    ON (
    `I18n__slug`.`content` = 'category-slug'
    AND `Category`.`id` = `I18n__slug`.`foreign_key`
    AND `I18n__slugs`.`model` = 'Category'
    AND `I18n__slug`.`field` = 'slug'
    AND `I18n__slug`.`locale` = 'eng')

在CakePHP中对大型i18n表的查询速度较慢

2 个答案: