René's URL Explorer Experiment


Title: JavaCore/resource/markdown/database/SQLOptimization.md at master · iCodeBoxFox/JavaCore · GitHub

Open Graph Title: JavaCore/resource/markdown/database/SQLOptimization.md at master · iCodeBoxFox/JavaCore

X Title: JavaCore/resource/markdown/database/SQLOptimization.md at master · iCodeBoxFox/JavaCore

Description: Java核心知识。集合框架、JVM机制、多线程与并发框架、网络协议、SSM框架、MySQL、分布式、微服务、高并发与高可用等。 - JavaCore/resource/markdown/database/SQLOptimization.md at master · iCodeBoxFox/JavaCore

Open Graph Description: Java核心知识。集合框架、JVM机制、多线程与并发框架、网络协议、SSM框架、MySQL、分布式、微服务、高并发与高可用等。 - iCodeBoxFox/JavaCore

X Description: Java核心知识。集合框架、JVM机制、多线程与并发框架、网络协议、SSM框架、MySQL、分布式、微服务、高并发与高可用等。 - iCodeBoxFox/JavaCore

Opengraph URL: https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md

X: @github

direct link

Domain: github.com

route-pattern/:user_id/:repository/blob/*name(/*path)
route-controllerblob
route-actionshow
fetch-noncev2:7739bd65-4587-016b-fee2-981ad8909da0
current-catalog-service-hashf3abb0cc802f3d7b95fc8762b94bdcb13bf39634c40c357301c4aa1d67a256fb
request-idA266:210405:80E097E:ACA4560:6A5E2C2B
html-safe-nonce805ea75506f9a1e8be79c5f76395ffa0071af03e9666d7eab154f6e0bdafa3da
visitor-payloadeyJyZWZlcnJlciI6IiIsInJlcXVlc3RfaWQiOiJBMjY2OjIxMDQwNTo4MEUwOTdFOkFDQTQ1NjA6NkE1RTJDMkIiLCJ2aXNpdG9yX2lkIjoiMzI5OTcwMTc2MzMwMjM3MDM0NyIsInJlZ2lvbl9lZGdlIjoiaWFkIiwicmVnaW9uX3JlbmRlciI6ImlhZCJ9
visitor-hmace25638e188b9793b9e85d06bde2d0f6c8c4f82125fa2e9b28d72640177116aac
hovercard-subject-tagrepository:311629029
github-keyboard-shortcutsrepository,source-code,file-tree,copilot
google-site-verificationApib7-x98H0j5cPqHWwSMm6dNU4GmODRoqxLiDzdx9I
octolytics-urlhttps://collector.github.com/github/collect
analytics-location///blob/show
fb:app_id1401488693436528
apple-itunes-appapp-id=1477376905, app-argument=https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md
twitter:imagehttps://opengraph.githubassets.com/830b28b05f2ad5dba31cd5cd755c4f309a584b6e461c2af5d82e7381ba097ff2/iCodeBoxFox/JavaCore
twitter:cardsummary_large_image
og:imagehttps://opengraph.githubassets.com/830b28b05f2ad5dba31cd5cd755c4f309a584b6e461c2af5d82e7381ba097ff2/iCodeBoxFox/JavaCore
og:image:altJava核心知识。集合框架、JVM机制、多线程与并发框架、网络协议、SSM框架、MySQL、分布式、微服务、高并发与高可用等。 - iCodeBoxFox/JavaCore
og:image:width1200
og:image:height600
og:site_nameGitHub
og:typeobject
hostnamegithub.com
expected-hostnamegithub.com
None621588b5bccbeb4b6fab0bb72b5de86200d5e6df07dbdabbdb667c8649f6e38d
turbo-cache-controlno-cache
go-importgithub.com/iCodeBoxFox/JavaCore git https://github.com/iCodeBoxFox/JavaCore.git
octolytics-dimension-user_id49975228
octolytics-dimension-user_loginiCodeBoxFox
octolytics-dimension-repository_id311629029
octolytics-dimension-repository_nwoiCodeBoxFox/JavaCore
octolytics-dimension-repository_publictrue
octolytics-dimension-repository_is_forktrue
octolytics-dimension-repository_parent_id153037149
octolytics-dimension-repository_parent_nwohicf/JavaCore
octolytics-dimension-repository_network_root_id153037149
octolytics-dimension-repository_network_root_nwohicf/JavaCore
turbo-body-classeslogged-out env-production page-responsive
disable-turbofalse
browser-stats-urlhttps://api.github.com/_private/browser/stats
browser-errors-urlhttps://api.github.com/_private/browser/errors
release14f1e1fce2dc2d662cbf7ef602c59756c2283f9e
ui-targetfull
theme-color#1e2327
color-schemelight dark

Links:

Skip to contenthttps://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#start-of-content
https://github.com/
Sign in https://github.com/login?return_to=https%3A%2F%2Fgithub.com%2FiCodeBoxFox%2FJavaCore%2Fblob%2Fmaster%2Fresource%2Fmarkdown%2Fdatabase%2FSQLOptimization.md
GitHub CopilotWrite better code with AIhttps://github.com/features/copilot
GitHub Copilot appDirect agents from issue to mergehttps://github.com/features/ai/github-app
MCP RegistryNewIntegrate external toolshttps://github.com/mcp
ActionsAutomate any workflowhttps://github.com/features/actions
CodespacesInstant dev environmentshttps://github.com/features/codespaces
IssuesPlan and track workhttps://github.com/features/issues
Code ReviewManage code changeshttps://github.com/features/code-review
GitHub Advanced SecurityFind and fix vulnerabilitieshttps://github.com/security/advanced-security
Code securitySecure your code as you buildhttps://github.com/security/advanced-security/code-security
Secret protectionStop leaks before they starthttps://github.com/security/advanced-security/secret-protection
Why GitHubhttps://github.com/why-github
Documentationhttps://docs.github.com
Bloghttps://github.blog
Changeloghttps://github.blog/changelog
Marketplacehttps://github.com/marketplace
View all featureshttps://github.com/features
Enterpriseshttps://github.com/enterprise
Small and medium teamshttps://github.com/team
Startupshttps://github.com/enterprise/startups
Nonprofitshttps://github.com/solutions/industry/nonprofits
App Modernizationhttps://github.com/solutions/use-case/app-modernization
DevSecOpshttps://github.com/solutions/use-case/devsecops
DevOpshttps://github.com/solutions/use-case/devops
CI/CDhttps://github.com/solutions/use-case/ci-cd
View all use caseshttps://github.com/solutions/use-case
Healthcarehttps://github.com/solutions/industry/healthcare
Financial serviceshttps://github.com/solutions/industry/financial-services
Manufacturinghttps://github.com/solutions/industry/manufacturing
Governmenthttps://github.com/solutions/industry/government
View all industrieshttps://github.com/solutions/industry
View all solutionshttps://github.com/solutions
AIhttps://github.com/resources/articles?topic=ai
Software Developmenthttps://github.com/resources/articles?topic=software-development
DevOpshttps://github.com/resources/articles?topic=devops
Securityhttps://github.com/resources/articles?topic=security
View all topicshttps://github.com/resources/articles
Customer storieshttps://github.com/customer-stories
Events & webinarshttps://github.com/resources/events
Ebooks & reportshttps://github.com/resources/whitepapers
Business insightshttps://github.com/solutions/executive-insights
GitHub Skillshttps://skills.github.com
Documentationhttps://docs.github.com
Customer supporthttps://support.github.com
Community forumhttps://github.com/orgs/community/discussions
Trust centerhttps://github.com/trust-center
Partnershttps://github.com/partners
View all resourceshttps://github.com/resources
GitHub SponsorsFund open source developershttps://github.com/open-source/sponsors
Security Labhttps://securitylab.github.com
Maintainer Communityhttps://maintainers.github.com
Acceleratorhttps://github.com/open-source/accelerator
GitHub Starshttps://stars.github.com
Archive Programhttps://archiveprogram.github.com
Topicshttps://github.com/topics
Trendinghttps://github.com/trending
Collectionshttps://github.com/collections
Enterprise platformAI-powered developer platformhttps://github.com/enterprise
GitHub Advanced SecurityEnterprise-grade security featureshttps://github.com/security/advanced-security
Copilot for BusinessEnterprise-grade AI featureshttps://github.com/features/copilot/copilot-business
Premium SupportEnterprise-grade 24/7 supporthttps://github.com/enterprise/premium-support
Pricinghttps://github.com/pricing
Search syntax tipshttps://docs.github.com/search-github/github-code-search/understanding-github-code-search-syntax
documentationhttps://docs.github.com/search-github/github-code-search/understanding-github-code-search-syntax
Sign in https://github.com/login?return_to=https%3A%2F%2Fgithub.com%2FiCodeBoxFox%2FJavaCore%2Fblob%2Fmaster%2Fresource%2Fmarkdown%2Fdatabase%2FSQLOptimization.md
Sign up https://github.com/signup?ref_cta=Sign+up&ref_loc=header+logged+out&ref_page=%2F%3Cuser-name%3E%2F%3Crepo-name%3E%2Fblob%2Fshow&source=header-repo&source_repo=iCodeBoxFox%2FJavaCore
Reloadhttps://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md
Reloadhttps://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md
Reloadhttps://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md
iCodeBoxFox https://github.com/iCodeBoxFox
JavaCorehttps://github.com/iCodeBoxFox/JavaCore
hicf/JavaCorehttps://github.com/hicf/JavaCore
Notifications https://github.com/login?return_to=%2FiCodeBoxFox%2FJavaCore
Fork 0 https://github.com/login?return_to=%2FiCodeBoxFox%2FJavaCore
Star 0 https://github.com/login?return_to=%2FiCodeBoxFox%2FJavaCore
Code https://github.com/iCodeBoxFox/JavaCore
Pull requests 0 https://github.com/iCodeBoxFox/JavaCore/pulls
Actions https://github.com/iCodeBoxFox/JavaCore/actions
Projects https://github.com/iCodeBoxFox/JavaCore/projects
Security and quality 0 https://github.com/iCodeBoxFox/JavaCore/security
Insights https://github.com/iCodeBoxFox/JavaCore/pulse
Code https://github.com/iCodeBoxFox/JavaCore
Pull requests https://github.com/iCodeBoxFox/JavaCore/pulls
Actions https://github.com/iCodeBoxFox/JavaCore/actions
Projects https://github.com/iCodeBoxFox/JavaCore/projects
Security and quality https://github.com/iCodeBoxFox/JavaCore/security
Insights https://github.com/iCodeBoxFox/JavaCore/pulse
https://github.com/iCodeBoxFox/JavaCore
JavaCorehttps://github.com/iCodeBoxFox/JavaCore/tree/master
resourcehttps://github.com/iCodeBoxFox/JavaCore/tree/master/resource
markdownhttps://github.com/iCodeBoxFox/JavaCore/tree/master/resource/markdown
databasehttps://github.com/iCodeBoxFox/JavaCore/tree/master/resource/markdown/database
Historyhttps://github.com/iCodeBoxFox/JavaCore/commits/master/resource/markdown/database/SQLOptimization.md
https://github.com/iCodeBoxFox/JavaCore/commits/master/resource/markdown/database/SQLOptimization.md
JavaCorehttps://github.com/iCodeBoxFox/JavaCore/tree/master
resourcehttps://github.com/iCodeBoxFox/JavaCore/tree/master/resource
markdownhttps://github.com/iCodeBoxFox/JavaCore/tree/master/resource/markdown
databasehttps://github.com/iCodeBoxFox/JavaCore/tree/master/resource/markdown/database
Rawhttps://github.com/iCodeBoxFox/JavaCore/raw/refs/heads/master/resource/markdown/database/SQLOptimization.md
https://github.com/about-cloud/JavaCorehttps://github.com/about-cloud/JavaCore
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#一优化必备的-explain-命令
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#二索引优化
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#1禁止无边界范围查询-------否则不会命中索引
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#2禁止无边界范围查询-not-in--否则不会命中索引
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#3禁止-左模糊-或-全模糊-查询否则不会命中索引
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#4字段的默认值不要为-null否则不会命中索引
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#5在-字段上计算-后不会命中索引
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#6组合索引-的-最左前缀原则
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#7关于-number-类型的字段不加单引号也会走索引亲测有效
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#8对于多表-join-时的-on-条件中字段类型一定要一致否则也不会命中索引
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#9varchar查询性能比-bigint-好亲测有效
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#10小数类型使用-decimal禁止使用-float-与-double
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#11表达是否的概念时字段使用is_开头数据类型使用-unsigned-tinyint类型1表示是0表示否
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#12任何非负数都必须声明为unsigned类型
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#13如果存储的字符串长度几乎相等必须使用char定长字符串类型
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#14有时候是不需要建索引
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#15单表行数超过-500万行-或者单表容量超过-2g才推荐分表
https://github.com/iCodeBoxFox/JavaCore/blob/master/resource/markdown/database/SQLOptimization.md#16进行-update-或-delete-时必先-selete避免出现误删数据
https://github.com
Termshttps://docs.github.com/site-policy/github-terms/github-terms-of-service
Privacyhttps://docs.github.com/site-policy/privacy-policies/github-privacy-statement
Securityhttps://github.com/security
Statushttps://www.githubstatus.com/
Communityhttps://github.community/
Docshttps://docs.github.com/
Contacthttps://support.github.com?tags=dotcom-footer

Viewport: width=device-width

URLs of crawlers that visited me.