mysql - Magento:MySql 显示缺少索引的慢查询

Question

我正在检查 Magento 1.8.1 的性能问题，我在 my.ini 中启用了以下 MySql 参数:

log_queries_not_using_indexes = 1
log_slow_admin_statements = 1
slow_query_log = 1
long_query_time = 1

我没有遇到任何慢查询(执行时间大于 1 秒)，但我有很多查询记录为缺少索引的联合查询。例如，其中之一是:

SELECT `t_d`.`entity_id`, `t_d`.`attribute_id`, `t_d`.`value` AS `default_value`, `t_s`.`value` AS `store_value`, IF(t_s.value_id IS NULL, t_d.value, t_s.value) AS `value` 
 FROM `catalog_product_entity_text` AS `t_d`
 LEFT JOIN `catalog_product_entity_text` AS `t_s` ON t_s.attribute_id = t_d.attribute_id AND t_s.entity_id = t_d.entity_id AND t_s.store_id = 1 WHERE (t_d.entity_type_id = 4) AND (t_d.entity_id IN (459, 444, 455, 450, 449, 458, 454, 443, 453)) AND (t_d.attribute_id IN ('73')) AND (t_d.store_id = 0) 
UNION ALL SELECT `t_d`.`entity_id`, `t_d`.`attribute_id`, `t_d`.`value` AS `default_value`, `t_s`.`value` AS `store_value`, IF(t_s.value_id IS NULL, t_d.value, t_s.value) AS `value` 
 FROM `catalog_product_entity_decimal` AS `t_d`
 LEFT JOIN `catalog_product_entity_decimal` AS `t_s` ON t_s.attribute_id = t_d.attribute_id AND t_s.entity_id = t_d.entity_id AND t_s.store_id = 1 WHERE (t_d.entity_type_id = 4) AND (t_d.entity_id IN (459, 444, 455, 450, 449, 458, 454, 443, 453)) AND (t_d.attribute_id IN ('76', '80', '120')) AND (t_d.store_id = 0) 
UNION ALL SELECT `t_d`.`entity_id`, `t_d`.`attribute_id`, `t_d`.`value` AS `default_value`, `t_s`.`value` AS `store_value`, IF(t_s.value_id IS NULL, t_d.value, t_s.value) AS `value` 
 FROM `catalog_product_entity_datetime` AS `t_d`
 LEFT JOIN `catalog_product_entity_datetime` AS `t_s` ON t_s.attribute_id = t_d.attribute_id AND t_s.entity_id = t_d.entity_id AND t_s.store_id = 1 WHERE (t_d.entity_type_id = 4) AND (t_d.entity_id IN (459, 444, 455, 450, 449, 458, 454, 443, 453)) AND (t_d.attribute_id IN ('77', '78', '93', '94')) AND (t_d.store_id = 0) 
UNION ALL SELECT `t_d`.`entity_id`, `t_d`.`attribute_id`, `t_d`.`value` AS `default_value`, `t_s`.`value` AS `store_value`, IF(t_s.value_id IS NULL, t_d.value, t_s.value) AS `value` 
 FROM `catalog_product_entity_varchar` AS `t_d`
 LEFT JOIN `catalog_product_entity_varchar` AS `t_s` ON t_s.attribute_id = t_d.attribute_id AND t_s.entity_id = t_d.entity_id AND t_s.store_id = 1 WHERE (t_d.entity_type_id = 4) AND (t_d.entity_id IN (459, 444, 455, 450, 449, 458, 454, 443, 453)) AND (t_d.attribute_id IN ('86', '87', '97', '112', '113', '114', '118', '119', '176')) AND (t_d.store_id = 0) 
UNION ALL SELECT `t_d`.`entity_id`, `t_d`.`attribute_id`, `t_d`.`value` AS `default_value`, `t_s`.`value` AS `store_value`, IF(t_s.value_id IS NULL, t_d.value, t_s.value) AS `value` 
 FROM `catalog_product_entity_int` AS `t_d`
 LEFT JOIN `catalog_product_entity_int` AS `t_s` ON t_s.attribute_id = t_d.attribute_id AND t_s.entity_id = t_d.entity_id AND t_s.store_id = 1 WHERE (t_d.entity_type_id = 4) AND (t_d.entity_id IN (459, 444, 455, 450, 449, 458, 454, 443, 453)) AND (t_d.attribute_id IN ('96', '121', '123', '125', '126', '127', '128', '131', '192', '193')) AND (t_d.store_id = 0);

如果我检查表，索引就在那里......所以不清楚为什么 MySql 将查询记录为未索引，同样在 Phpmyadmin 中我注意到有太多查询没有使用索引。

这是描述输出: Describe Output

我已经尝试了 OPTIMIZE TABLE，但仍然记录了非索引查询。

关于如何修复这个问题有什么建议吗？

谢谢。

Answer 1

我不喜欢 log_queries_not_using_indexes = 1 因为你发现的原因 -- 它使慢日志困惑，因为条目可能不值得注意。

设置的一个借口是当你开始一个项目时， table 还很小。您可能忘记向最终会增长的表添加合适的索引。为此，我会打开它一天，然后查看输出，添加缺失的索引，然后永远关闭它。

对于那个查询，我会

 t_d:  INDEX(entity_type_id, store_id, attribute_id, entity_id)
 t_s:  INDEX(entity_type_id, store_id)

entity_type_id 和 store_id 可以交换，但我怀疑这是否重要。

OPTIMIZE TABLE 不太可能影响索引的使用。如果表是 InnoDB(它们应该是)，您可能永远不会从 OPTIMIZE TABLE 中受益。

哦，糟糕! 4 个表包含 4 种不同的数据类型。随着数据的增长，您将遇到麻烦。 EAV 不好；你让事情变得更糟。