search
HomeBackend DevelopmentPHP TutorialWhat is the underlying principle of MySQL Update operation? How is the performance of a large number of row updates? Will updating large batches of data in transactions be prone to deadlocks?

What is the underlying principle of MySQL Update operation? How is the performance of a large number of row updates? Will updating large batches of data in transactions be prone to deadlocks?

In-depth exploration of MySQL Update operations: Principles, Performance and Deadlock Risks

In database applications, UPDATE operation is crucial, especially in high concurrency scenarios, its performance and deadlock problems have attracted much attention. This article will conduct in-depth analysis of the underlying mechanisms of MySQL UPDATE operations, the performance bottlenecks of large-scale updates, and the risk of deadlocks that may be caused by large-scale updates in transactions.

The underlying mechanism of MySQL UPDATE operation

The MySQL UPDATE statement execution process includes multiple stages: SQL parsing, condition matching, row locking, and data update. The specific steps are as follows:

  1. SQL parsing: The MySQL parser converts UPDATE statements into internal executable instructions.
  2. Conditional matching: According to the WHERE clause, the MySQL engine scans the table to find rows that meet the criteria.
  3. Row lock: Use row-level lock to lock the rows that need to be updated to prevent concurrent modification conflicts.
  4. Data update: The update operation is performed in the memory buffer and then written to disk.

Performance challenges of large-scale data updates

Performance issues may be highlighted when the number of update rows is huge (for example, the thousand-row to ten thousand-row levels). The main influencing factors include:

  • Lock competition: Lock competition intensifies lock competition in large quantities, especially in high concurrent read and write environments.
  • Buffer pressure: Large batch updates may exhaust buffer resources, causing other operations to block.
  • Disk I/O: Frequent disk I/O operations have become a performance bottleneck.

The risk of deadlocks for large batch updates in transactions

In high concurrency environments, performing large batches of UPDATE operations in transactions is prone to deadlocks. The reason is:

  • Row-level lock: Multiple transactions update the same batch of data at the same time, which may form a circular dependency lock waiting, which ultimately leads to a deadlock. For example, transaction A locks row 1, transaction B locks row 2, then A tries to lock row 2, and B tries to lock row 1, resulting in a deadlock.
  • Lock Waiting Time: Long lock waiting may cause a timeout, which triggers a deadlock.

To reduce the risk of deadlock, the following strategies are recommended:

  • Optimize transactions: Reduce transaction scope and reduce lock holding time.
  • Batch update: Split large batch updates into multiple small batches, execute them in batches, and reduce lock competition.
  • Index optimization: Create appropriate indexes to reduce data scanning and reduce lock overhead.

Through in-depth analysis of the underlying mechanisms, performance bottlenecks and deadlock risks of MySQL UPDATE operations, we can better understand and optimize database operations and improve system performance and stability.

The above is the detailed content of What is the underlying principle of MySQL Update operation? How is the performance of a large number of row updates? Will updating large batches of data in transactions be prone to deadlocks?. For more information, please follow other related articles on the PHP Chinese website!

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
图文详解mysql架构原理图文详解mysql架构原理May 17, 2022 pm 05:54 PM

本篇文章给大家带来了关于mysql的相关知识,其中主要介绍了关于架构原理的相关内容,MySQL Server架构自顶向下大致可以分网络连接层、服务层、存储引擎层和系统文件层,下面一起来看一下,希望对大家有帮助。

mysql怎么替换换行符mysql怎么替换换行符Apr 18, 2022 pm 03:14 PM

在mysql中,可以利用char()和REPLACE()函数来替换换行符;REPLACE()函数可以用新字符串替换列中的换行符,而换行符可使用“char(13)”来表示,语法为“replace(字段名,char(13),'新字符串') ”。

mysql怎么去掉第一个字符mysql怎么去掉第一个字符May 19, 2022 am 10:21 AM

方法:1、利用right函数,语法为“update 表名 set 指定字段 = right(指定字段, length(指定字段)-1)...”;2、利用substring函数,语法为“select substring(指定字段,2)..”。

mysql的msi与zip版本有什么区别mysql的msi与zip版本有什么区别May 16, 2022 pm 04:33 PM

mysql的msi与zip版本的区别:1、zip包含的安装程序是一种主动安装,而msi包含的是被installer所用的安装文件以提交请求的方式安装;2、zip是一种数据压缩和文档存储的文件格式,msi是微软格式的安装包。

mysql怎么将varchar转换为int类型mysql怎么将varchar转换为int类型May 12, 2022 pm 04:51 PM

转换方法:1、利用cast函数,语法“select * from 表名 order by cast(字段名 as SIGNED)”;2、利用“select * from 表名 order by CONVERT(字段名,SIGNED)”语句。

MySQL复制技术之异步复制和半同步复制MySQL复制技术之异步复制和半同步复制Apr 25, 2022 pm 07:21 PM

本篇文章给大家带来了关于mysql的相关知识,其中主要介绍了关于MySQL复制技术的相关问题,包括了异步复制、半同步复制等等内容,下面一起来看一下,希望对大家有帮助。

带你把MySQL索引吃透了带你把MySQL索引吃透了Apr 22, 2022 am 11:48 AM

本篇文章给大家带来了关于mysql的相关知识,其中主要介绍了mysql高级篇的一些问题,包括了索引是什么、索引底层实现等等问题,下面一起来看一下,希望对大家有帮助。

mysql怎么判断是否是数字类型mysql怎么判断是否是数字类型May 16, 2022 am 10:09 AM

在mysql中,可以利用REGEXP运算符判断数据是否是数字类型,语法为“String REGEXP '[^0-9.]'”;该运算符是正则表达式的缩写,若数据字符中含有数字时,返回的结果是true,反之返回的结果是false。

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

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
1 months agoBy尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌

Hot Tools

SAP NetWeaver Server Adapter for Eclipse

SAP NetWeaver Server Adapter for Eclipse

Integrate Eclipse with SAP NetWeaver application server.

EditPlus Chinese cracked version

EditPlus Chinese cracked version

Small size, syntax highlighting, does not support code prompt function

Dreamweaver Mac version

Dreamweaver Mac version

Visual web development tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

VSCode Windows 64-bit Download

VSCode Windows 64-bit Download

A free and powerful IDE editor launched by Microsoft