search
HomeBackend DevelopmentPHP TutorialMySQL分页性能问题,Limit 性能问题求解决!

众所周知,Mysql分页就要用到Limit进行分页,数据量/分页数小的时候Limit性能是可想而知的。 如:

SELECT pid,author,hash,dateline FROM posts WHERE pid='123456' ORDER BY pid ASC LIMIT 100,100;

上述SQL语句性能没有任何问题。

但是,如果当offset便宜了过大的情况就会出现性能瓶颈。 如:

SELECT pid,author,hash,dateline FROM posts WHERE pid='123456' ORDER BY pid ASC LIMIT 159000,100;

若要解决Limit offset过大的时候,可以采用子查询的方法进行分页。 如:

SELECT pid,author,hash,dateline FROM posts ORDER BY pid ASC LIMIT 159000,100;

等价于:

SELECT pid,author,hash,dateline FROM posts WHERE pid>=(SELECT pid FROM posts LIMIT 159000,1)ORDER BY pid ASC LIMIT 100;

此时的性能是纯粹LIMIT 159000,100 的几倍至高。

但是问题又来了,子查询又必须是数据连续,所以无法加入WHERE查询条件,如:

SELECT tid,pid,author,hash,dateline FROM posts WHERE tid=10 AND pid>=(SELECT pid FROM posts LIMIT 159000,1)ORDER BY pid ASC LIMIT 100;

此时的结果并非我想要的结果。

所以求高性能解决LIMIT分页的方法。 在线等。

============================ PS: pid 为主键

回复内容:

众所周知,Mysql分页就要用到Limit进行分页,数据量/分页数小的时候Limit性能是可想而知的。 如:

SELECT pid,author,hash,dateline FROM posts WHERE pid='123456' ORDER BY pid ASC LIMIT 100,100;

上述SQL语句性能没有任何问题。

但是,如果当offset便宜了过大的情况就会出现性能瓶颈。 如:

SELECT pid,author,hash,dateline FROM posts WHERE pid='123456' ORDER BY pid ASC LIMIT 159000,100;

若要解决Limit offset过大的时候,可以采用子查询的方法进行分页。 如:

SELECT pid,author,hash,dateline FROM posts ORDER BY pid ASC LIMIT 159000,100;

等价于:

SELECT pid,author,hash,dateline FROM posts WHERE pid>=(SELECT pid FROM posts LIMIT 159000,1)ORDER BY pid ASC LIMIT 100;

此时的性能是纯粹LIMIT 159000,100 的几倍至高。

但是问题又来了,子查询又必须是数据连续,所以无法加入WHERE查询条件,如:

SELECT tid,pid,author,hash,dateline FROM posts WHERE tid=10 AND pid>=(SELECT pid FROM posts LIMIT 159000,1)ORDER BY pid ASC LIMIT 100;

此时的结果并非我想要的结果。

所以求高性能解决LIMIT分页的方法。 在线等。

============================ PS: pid 为主键

这篇PDF可以解决你的问题

Efficient Pagination Using MySQL

你的pid是啥,不是主键吗?最后一条 pid=10 AND pid>=(SELECT pid FROM posts LIMIT 159000,1) 有能同时成立吗

外面有的条件,子查询里面照样写就行了,和子查询的条件相同,order by相同,比如: select * from user where sex=2 and issingle=0 and id

<code>    ALTER TABLE `posts `  ADD INDEX `tid_pid` USING BTREE (`tid`,`pid`) comment '';
</code>
Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Optimize PHP Code: Reducing Memory Usage & Execution TimeOptimize PHP Code: Reducing Memory Usage & Execution TimeMay 10, 2025 am 12:04 AM

TooptimizePHPcodeforreducedmemoryusageandexecutiontime,followthesesteps:1)Usereferencesinsteadofcopyinglargedatastructurestoreducememoryconsumption.2)LeveragePHP'sbuilt-infunctionslikearray_mapforfasterexecution.3)Implementcachingmechanisms,suchasAPC

PHP Email: Step-by-Step Sending GuidePHP Email: Step-by-Step Sending GuideMay 09, 2025 am 12:14 AM

PHPisusedforsendingemailsduetoitsintegrationwithservermailservicesandexternalSMTPproviders,automatingnotificationsandmarketingcampaigns.1)SetupyourPHPenvironmentwithawebserverandPHP,ensuringthemailfunctionisenabled.2)UseabasicscriptwithPHP'smailfunct

How to Send Email via PHP: Examples & CodeHow to Send Email via PHP: Examples & CodeMay 09, 2025 am 12:13 AM

The best way to send emails is to use the PHPMailer library. 1) Using the mail() function is simple but unreliable, which may cause emails to enter spam or cannot be delivered. 2) PHPMailer provides better control and reliability, and supports HTML mail, attachments and SMTP authentication. 3) Make sure SMTP settings are configured correctly and encryption (such as STARTTLS or SSL/TLS) is used to enhance security. 4) For large amounts of emails, consider using a mail queue system to optimize performance.

Advanced PHP Email: Custom Headers & FeaturesAdvanced PHP Email: Custom Headers & FeaturesMay 09, 2025 am 12:13 AM

CustomheadersandadvancedfeaturesinPHPemailenhancefunctionalityandreliability.1)Customheadersaddmetadatafortrackingandcategorization.2)HTMLemailsallowformattingandinteractivity.3)AttachmentscanbesentusinglibrarieslikePHPMailer.4)SMTPauthenticationimpr

Guide to Sending Emails with PHP & SMTPGuide to Sending Emails with PHP & SMTPMay 09, 2025 am 12:06 AM

Sending mail using PHP and SMTP can be achieved through the PHPMailer library. 1) Install and configure PHPMailer, 2) Set SMTP server details, 3) Define the email content, 4) Send emails and handle errors. Use this method to ensure the reliability and security of emails.

What is the best way to send an email using PHP?What is the best way to send an email using PHP?May 08, 2025 am 12:21 AM

ThebestapproachforsendingemailsinPHPisusingthePHPMailerlibraryduetoitsreliability,featurerichness,andeaseofuse.PHPMailersupportsSMTP,providesdetailederrorhandling,allowssendingHTMLandplaintextemails,supportsattachments,andenhancessecurity.Foroptimalu

Best Practices for Dependency Injection in PHPBest Practices for Dependency Injection in PHPMay 08, 2025 am 12:21 AM

The reason for using Dependency Injection (DI) is that it promotes loose coupling, testability, and maintainability of the code. 1) Use constructor to inject dependencies, 2) Avoid using service locators, 3) Use dependency injection containers to manage dependencies, 4) Improve testability through injecting dependencies, 5) Avoid over-injection dependencies, 6) Consider the impact of DI on performance.

PHP performance tuning tips and tricksPHP performance tuning tips and tricksMay 08, 2025 am 12:20 AM

PHPperformancetuningiscrucialbecauseitenhancesspeedandefficiency,whicharevitalforwebapplications.1)CachingwithAPCureducesdatabaseloadandimprovesresponsetimes.2)Optimizingdatabasequeriesbyselectingnecessarycolumnsandusingindexingspeedsupdataretrieval.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

WebStorm Mac version

WebStorm Mac version

Useful JavaScript development tools

SublimeText3 Linux new version

SublimeText3 Linux new version

SublimeText3 Linux latest version

SecLists

SecLists

SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Safe Exam Browser

Safe Exam Browser

Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.