mysql - 如何分析 WordPress 安装的慢查询日志？

Question

我在安装 WordPress 时遇到了一些性能问题。我运行了多个慢查询测试，虽然我确实看到它们之间存在一些一致性，但我仍然无法查明问题所在。以下是我多次看到的一些查询:

SET timestamp=1333980631;
SELECT SQL_CALC_FOUND_ROWS wp_posts.* FROM wp_posts INNER JOIN wp_term_relationships ON (wp_posts.ID = wp_term_relationships.object_id) WHERE 1=1 AND ( wp_term_relationships.term_taxonomy_id IN (1442,4054) ) AND wp_posts.post_type = 'post' AND (wp_posts.post_status = 'publish' OR wp_posts.post_status = 'private') GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC LIMIT 0, 2;

和

### 1 Query 
### Total time: 3.015405, Average time: 3.015405
### Taking 3.015405 seconds to complete
### Rows analyzed 60
SET timestamp=XXX;
SELECT SQL_CALC_FOUND_ROWS wp_posts.* FROM wp_posts INNER JOIN wp_term_relationships ON (wp_posts.ID = wp_term_relationships.object_id) WHERE XXX=XXX AND ( wp_term_relationships.term_taxonomy_id IN (XXX) ) AND wp_posts.post_type = 'XXX' AND (wp_posts.post_status = 'XXX') GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC LIMIT XXX, XXX;

SET timestamp=1334004964;
SELECT SQL_CALC_FOUND_ROWS wp_posts.* FROM wp_posts INNER JOIN wp_term_relationships ON (wp_posts.ID = wp_term_relationships.object_id) WHERE 1=1 AND ( wp_term_relationships.term_taxonomy_id IN (125) ) AND wp_posts.post_type = 'post' AND (wp_posts.post_status = 'publish') GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC LIMIT 0, 8;

和

### 1 Query 
### Total time: 1.593301, Average time: 1.593301
### Taking 1.593301 seconds to complete
### Rows analyzed 19755
SET timestamp=XXX;
SELECT /*!XXX SQL_NO_CACHE */ * FROM `wp_posts`;

SET timestamp=1333978522;
SELECT /*!40001 SQL_NO_CACHE */ * FROM `wp_posts`;

我注意到 wp_term_taxonomy 似乎出现了，还有 wp_posts 和其他一些。我的问题是，如何缩小这些结果的范围并找出问题所在？

Answer 1

你可以:

1. 使用plugin performance profiler对有问题的插件进行基准测试和查明
2. 使用new relic找到问题
3. 使用Debug Objects为查询转储数据等。

您显示的查询看起来像通常的 wp-admin 查询，或用于定义要在列表中显示多少页的寻呼机查询。

您也可以尝试最简单的方法 - 一个接一个地禁用插件以确定是哪个插件产生了您的问题查询。