This article brings you relevant knowledge about mysql, which mainly organizes issues related to log management, including error logs, general query logs, binary logs, etc. The following is Let's take a look, hope it helps everyone.

Recommended learning: mysql video tutorial
MySQL logs are saved in the storage directory of the database file by default (usually /usr/ local/mysql/data/). You can also modify the configuration file to customize the storage location of the log files.
When I was compiling and installing, the database file storage directory was set to /home/mysql.
1. Introduction to four types of logs
1.1 Error log
The error log is used to record error information that occurs when MySQL starts, stops or runs. It is enabled by default.
vim /etc/my.cnf
[mysqld]
log-error=/home/mysql/mysql_error.log #Specify the storage location of the log
1.2 General query log
The general query log is used to record all connections and statements of MySQL. It is closed by default.
vim /etc/my.cnf [mysqld] general_log=ON general_log_file=/home/mysql/mysql_general.log
1.3 Binary log
Binary log (binlog) is used to record all statements that have updated data or have potentially updated data. It records data changes and can be used for data recovery. Default Turned on.
vim /etc/my.cnf [mysqld] log-bin=mysql-bin #也可以log_bin=mysql-bin #使用相对路径,则文件存储在默认目录/usr/local/mysql/data/中
1.4 Slow query log
The slow query log is used to record all statements whose execution time exceeds long_query_time seconds. You can find which query statements take a long time to execute for optimization. It is turned off by default. .
vim /etc/my.cnf [mysqld] slow_query_log=ON slow_query_log_file=/home/mysql/mysql_slow_query.log long_query_time=5 #慢查询时间,设置超过5秒执行的语句被记录,缺省时为10秒
2. Configure four types of logs:
Step 1: Modify the configuration file /etc/my.cnf
vim /etc/my.cnf [mysqld] ##错误日志,用来记录当MySQL启动、停止或运行时发生的错误信息,默认已开启 log-error=/home/mysql/mysql_error.log ##通用查询日志,用来记录MySQL的所有连接和语句,默认是关闭的 general_log=ON general_log_file=/home/mysql/mysql_general.log ##二进制日志(binlog),用来记录所有更新了数据或者已经潜在更新了数据的语句,记录了数据的更改,可用于数据恢复,默认已开启 log-bin=mysql-bin #也可以log_bin=mysql-bin #使用相对路径,则文件存储在默认目录/home/mysql/中 ##慢查询日志,用来记录所有执行时间超过long_query_time秒的语句,可以找到哪些查询语句执行时间长,以便于优化,默认是关闭的 slow_query_log=ON slow_query_log_file=/home/mysql/mysql_slow_query.log long_query_time=5 #慢查询时间,设置超过5秒执行的语句被记录,缺省时为10秒
Step 2: Restart the service
systemctl restart mysqld


3. Query whether the log is enabled
mysql -u root -p[密码] #查看错误日志存放位置 show variables like 'log_error'; #查看通用查询日志是否开启 show variables like 'general%'; #查看二进制日志是否开启 show variables like 'log_bin%'; #查看慢查询日功能是否开启 show variables like '%slow%'; #查看慢查询时间设置 show variables like 'long_query_time'; #在数据库中设置开启慢查询的方法,即以修改变量值的方式开启。但重启服务后会失效。 set global slow_query_log=ON;
4. Split the binary log
# The ##mysql-bin.index file will split the binary log. Every time mysql is restarted or after "flush logs" refreshes the log in the database, a new binary log will be generated.

The above is the detailed content of MySQL log management (summary sharing). For more information, please follow other related articles on the PHP Chinese website!
Explain the InnoDB Buffer Pool and its importance for performance.Apr 19, 2025 am 12:24 AMInnoDBBufferPool reduces disk I/O by caching data and indexing pages, improving database performance. Its working principle includes: 1. Data reading: Read data from BufferPool; 2. Data writing: After modifying the data, write to BufferPool and refresh it to disk regularly; 3. Cache management: Use the LRU algorithm to manage cache pages; 4. Reading mechanism: Load adjacent data pages in advance. By sizing the BufferPool and using multiple instances, database performance can be optimized.
MySQL vs. Other Programming Languages: A ComparisonApr 19, 2025 am 12:22 AMCompared with other programming languages, MySQL is mainly used to store and manage data, while other languages such as Python, Java, and C are used for logical processing and application development. MySQL is known for its high performance, scalability and cross-platform support, suitable for data management needs, while other languages have advantages in their respective fields such as data analytics, enterprise applications, and system programming.
Learning MySQL: A Step-by-Step Guide for New UsersApr 19, 2025 am 12:19 AMMySQL is worth learning because it is a powerful open source database management system suitable for data storage, management and analysis. 1) MySQL is a relational database that uses SQL to operate data and is suitable for structured data management. 2) The SQL language is the key to interacting with MySQL and supports CRUD operations. 3) The working principle of MySQL includes client/server architecture, storage engine and query optimizer. 4) Basic usage includes creating databases and tables, and advanced usage involves joining tables using JOIN. 5) Common errors include syntax errors and permission issues, and debugging skills include checking syntax and using EXPLAIN commands. 6) Performance optimization involves the use of indexes, optimization of SQL statements and regular maintenance of databases.
MySQL: Essential Skills for Beginners to MasterApr 18, 2025 am 12:24 AMMySQL is suitable for beginners to learn database skills. 1. Install MySQL server and client tools. 2. Understand basic SQL queries, such as SELECT. 3. Master data operations: create tables, insert, update, and delete data. 4. Learn advanced skills: subquery and window functions. 5. Debugging and optimization: Check syntax, use indexes, avoid SELECT*, and use LIMIT.
MySQL: Structured Data and Relational DatabasesApr 18, 2025 am 12:22 AMMySQL efficiently manages structured data through table structure and SQL query, and implements inter-table relationships through foreign keys. 1. Define the data format and type when creating a table. 2. Use foreign keys to establish relationships between tables. 3. Improve performance through indexing and query optimization. 4. Regularly backup and monitor databases to ensure data security and performance optimization.
MySQL: Key Features and Capabilities ExplainedApr 18, 2025 am 12:17 AMMySQL is an open source relational database management system that is widely used in Web development. Its key features include: 1. Supports multiple storage engines, such as InnoDB and MyISAM, suitable for different scenarios; 2. Provides master-slave replication functions to facilitate load balancing and data backup; 3. Improve query efficiency through query optimization and index use.
The Purpose of SQL: Interacting with MySQL DatabasesApr 18, 2025 am 12:12 AMSQL is used to interact with MySQL database to realize data addition, deletion, modification, inspection and database design. 1) SQL performs data operations through SELECT, INSERT, UPDATE, DELETE statements; 2) Use CREATE, ALTER, DROP statements for database design and management; 3) Complex queries and data analysis are implemented through SQL to improve business decision-making efficiency.
MySQL for Beginners: Getting Started with Database ManagementApr 18, 2025 am 12:10 AMThe basic operations of MySQL include creating databases, tables, and using SQL to perform CRUD operations on data. 1. Create a database: CREATEDATABASEmy_first_db; 2. Create a table: CREATETABLEbooks(idINTAUTO_INCREMENTPRIMARYKEY, titleVARCHAR(100)NOTNULL, authorVARCHAR(100)NOTNULL, published_yearINT); 3. Insert data: INSERTINTObooks(title, author, published_year)VA


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

SublimeText3 English version
Recommended: Win version, supports code prompts!

SublimeText3 Chinese version
Chinese version, very easy to use

Dreamweaver Mac version
Visual web development tools

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft







