Home Database Mysql Tutorial mysql的死锁问题分析与处理方法

mysql的死锁问题分析与处理方法

Jun 07, 2016 pm 05:51 PM
MySQL死锁

前几天我的mysql突然出现大量死锁,全部需要一个个Kill id才能完成,下面我总结一下我最终解决死锁方法吧。

myISAM和MEMORY存储引擎采用的是表级锁table-level locking

死锁
所谓死锁: 是指两个或两个以上的进程在执行过程中,
因争夺资源而造成的一种互相等待的现象,若无外力作用,它们都将无法推进下去.
此时称系统处于死锁状态或系统产生了死锁,这些永远在互相等竺的进程称为死锁进程.
 
表级锁不会产生死锁.所以解决死锁主要还是真对于最常用的InnoDB.
 
在遇到问题时


先执行show processlist找到死锁线程号.然后Kill processNo
 
当然主要解决还是需要去看一下具体的操作.可能产生死锁
Show innodb status检查引擎状态 ,可以看到哪些语句产生死锁

SHOW PROCESSLIST查看数据库中表的状态,是否被锁;

kill id   //杀掉被锁的表

===================================================

 代码如下 复制代码

set autocommit=0;

select * from t1  where uid='xxxx' for update    //在有索引(例如uid)的情况下是行锁,否则是表锁

insert into t1 values(1,'xxxxx');

commit;

=====================================================

lock tables t1 write|read;

insert into t1 values(2,'xxxxx'); //只有insert

unlock tables;

解决办法

1、全表扫描,没有可用的索引。
2、解决把你程序中的SQL,把IN改成JOIN,
3、在mysql中的my.ini中把数据库连接时间改小点。

Statement of this Website
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

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

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

When might a full table scan be faster than using an index in MySQL? When might a full table scan be faster than using an index in MySQL? Apr 09, 2025 am 12:05 AM

Full table scanning may be faster in MySQL than using indexes. Specific cases include: 1) the data volume is small; 2) when the query returns a large amount of data; 3) when the index column is not highly selective; 4) when the complex query. By analyzing query plans, optimizing indexes, avoiding over-index and regularly maintaining tables, you can make the best choices in practical applications.

Explain InnoDB Full-Text Search capabilities. Explain InnoDB Full-Text Search capabilities. Apr 02, 2025 pm 06:09 PM

InnoDB's full-text search capabilities are very powerful, which can significantly improve database query efficiency and ability to process large amounts of text data. 1) InnoDB implements full-text search through inverted indexing, supporting basic and advanced search queries. 2) Use MATCH and AGAINST keywords to search, support Boolean mode and phrase search. 3) Optimization methods include using word segmentation technology, periodic rebuilding of indexes and adjusting cache size to improve performance and accuracy.

Can I install mysql on Windows 7 Can I install mysql on Windows 7 Apr 08, 2025 pm 03:21 PM

Yes, MySQL can be installed on Windows 7, and although Microsoft has stopped supporting Windows 7, MySQL is still compatible with it. However, the following points should be noted during the installation process: Download the MySQL installer for Windows. Select the appropriate version of MySQL (community or enterprise). Select the appropriate installation directory and character set during the installation process. Set the root user password and keep it properly. Connect to the database for testing. Note the compatibility and security issues on Windows 7, and it is recommended to upgrade to a supported operating system.

Difference between clustered index and non-clustered index (secondary index) in InnoDB. Difference between clustered index and non-clustered index (secondary index) in InnoDB. Apr 02, 2025 pm 06:25 PM

The difference between clustered index and non-clustered index is: 1. Clustered index stores data rows in the index structure, which is suitable for querying by primary key and range. 2. The non-clustered index stores index key values ​​and pointers to data rows, and is suitable for non-primary key column queries.

What are some popular MySQL GUI tools (e.g., MySQL Workbench, phpMyAdmin)? What are some popular MySQL GUI tools (e.g., MySQL Workbench, phpMyAdmin)? Mar 21, 2025 pm 06:28 PM

Article discusses popular MySQL GUI tools like MySQL Workbench and phpMyAdmin, comparing their features and suitability for beginners and advanced users.[159 characters]

How do you handle large datasets in MySQL? How do you handle large datasets in MySQL? Mar 21, 2025 pm 12:15 PM

Article discusses strategies for handling large datasets in MySQL, including partitioning, sharding, indexing, and query optimization.

MySQL: Simple Concepts for Easy Learning MySQL: Simple Concepts for Easy Learning Apr 10, 2025 am 09:29 AM

MySQL is an open source relational database management system. 1) Create database and tables: Use the CREATEDATABASE and CREATETABLE commands. 2) Basic operations: INSERT, UPDATE, DELETE and SELECT. 3) Advanced operations: JOIN, subquery and transaction processing. 4) Debugging skills: Check syntax, data type and permissions. 5) Optimization suggestions: Use indexes, avoid SELECT* and use transactions.

The relationship between mysql user and database The relationship between mysql user and database Apr 08, 2025 pm 07:15 PM

In MySQL database, the relationship between the user and the database is defined by permissions and tables. The user has a username and password to access the database. Permissions are granted through the GRANT command, while the table is created by the CREATE TABLE command. To establish a relationship between a user and a database, you need to create a database, create a user, and then grant permissions.

See all articles