translator
- Afrikaans
- Albanian - shqipe
- Arabic - العربية
- Armenian - Հայերէն
- Azerbaijani - azərbaycanca
- Basque - euskara
- Belarusian - беларуская
- Bengali - বাংলা
- Bulgarian - български
- Catalan - català
- Chinese - 中文(简体中文)
- Chinese - 中文 (繁體中文)
- Croatian - hrvatski
- Czech - čeština
- Danish - dansk
- Dutch - Nederlands
- English
- Esperanto - esperanto
- Estonian - eesti
- Filipino
- Finnish - suomi
- French - français
- Galician - galego
- Georgian - ქართული
- German - Deutsch
- Greek - Ελληνικά
- Gujarati - ગુજરાતી
- Haitian Creole - kreyòl ayisyen
- Hebrew - עברית
- Hindi - हिन्दी
- Hungarian - magyar
- Icelandic - íslenska
- Indonesian - Bahasa Indonesia
- Irish - Gaeilge
- Italian - italiano
- Japanese - 日本語
- Kannada - ಕನ್ನಡ
- Korean - 한국어
- Latin - Lingua Latina
- Latvian - latviešu
- Lithuanian - lietuvių
- Macedonian - македонски
- Malay - Bahasa Melayu
- Maltese - Malti
- Norwegian - norsk
- Persian - فارسی
- Polish - polski
- Portuguese - português
- Romanian - română
- Russian - русский
- Serbian - Српски
- Slovak - slovenčina
- Slovenian - slovenščina
- Spanish - español
- Swahili - Kiswahili
- Swedish - svenska
- Tamil - தமிழ்
- Telugu - తెలుగు
- Thai - ไทย
- Turkish - Türkçe
- Ukrainian - українська
- Urdu - اردو
- Vietnamese - Tiếng Việt
- Welsh - Cymraeg
- Yiddish - יידיש
- Afrikaans
- Albanian - shqipe
- Arabic - العربية
- Armenian - Հայերէն
- Azerbaijani - azərbaycanca
- Basque - euskara
- Belarusian - беларуская
- Bengali - বাংলা
- Bulgarian - български
- Catalan - català
- Chinese - 中文(简体中文)
- Chinese - 中文 (繁體中文)
- Croatian - hrvatski
- Czech - čeština
- Danish - dansk
- Dutch - Nederlands
- English
- Esperanto - esperanto
- Estonian - eesti
- Filipino
- Finnish - suomi
- French - français
- Galician - galego
- Georgian - ქართული
- German - Deutsch
- Greek - Ελληνικά
- Gujarati - ગુજરાતી
- Haitian Creole - kreyòl ayisyen
- Hebrew - עברית
- Hindi - हिन्दी
- Hungarian - magyar
- Icelandic - íslenska
- Indonesian - Bahasa Indonesia
- Irish - Gaeilge
- Italian - italiano
- Japanese - 日本語
- Kannada - ಕನ್ನಡ
- Korean - 한국어
- Latin - Lingua Latina
- Latvian - latviešu
- Lithuanian - lietuvių
- Macedonian - македонски
- Malay - Bahasa Melayu
- Maltese - Malti
- Norwegian - norsk
- Persian - فارسی
- Polish - polski
- Portuguese - português
- Romanian - română
- Russian - русский
- Serbian - Српски
- Slovak - slovenčina
- Slovenian - slovenščina
- Spanish - español
- Swahili - Kiswahili
- Swedish - svenska
- Tamil - தமிழ்
- Telugu - తెలుగు
- Thai - ไทย
- Turkish - Türkçe
- Ukrainian - українська
- Urdu - اردو
- Vietnamese - Tiếng Việt
- Welsh - Cymraeg
- Yiddish - יידיש
Group by 未加索引
- 使用的是临时表,加文件排序(数据量小用内存排序)
加个索引(一般是联合索引)
- 注意:这里加的索引一般不会仅仅是group by后面的字段索引(大多数多少条件是一个以该字段开头联合索引,方便使用覆盖索引或者索引下推)。如果该字段是一个varchar类型,最好加个int冗余字段,建立索引的字段,性能更高。
- 以该字段为条件的B+树自动排序,所以就会导致避免了排序和临时表这个过程,查询性能更快。
加了索引还是慢(查询结果的数据量太大)?
在读多写少场景:
1. 加个查询条件的统计表(Group by, order by 还是 count查询性能都不会太差)!!!!
2. 每次关联的表发生变化,就更新统计表。
3. 为了性能同时可以用缓存或者ES通过订阅同步该统计表。
标签:中文,Group,Chinese,sloven,查询,索引,MySQL From: https://www.cnblogs.com/black-joker/p/17841986.html