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我有这样一个查询:MySQL的提高查询性能
SELECT city.id, city.country_id, localization.lang , localization.name, ... some other fields ...
FROM city city
LEFT OUTER JOIN city_localization localization ON (localization.city_id = city.id)
WHERE city.country_id = '196' AND localization.lang = 'en'
ORDER BY localization.name
“城市” 表模式:
“city_localization” 表模式:
说明输出:
如何避免使用filesort和临时?
我不知道关于filesort和临时的,但我注意到你过滤左连接的右侧,用内连接取代它。应该在连接本身中过滤'city_localization':'LEFT OUTER JOIN city_localization localization ON(localization.city_id = city.id and localization.lang ='en')'。 – 2012-04-08 20:13:05