说明:
线上的一台MySQL数据库服务器突然断电,造成系统故障无法启动,重新安装系统后,找到之前的MySQL数据库文件夹。
问题:
通过复制文件的方式对之前的MySQL数据库进行恢复,发现在程序调用时找不到数据库中的表,造成网站无法正常访问。
分析:
1、MySQL数据库,使用拷贝文件方式来恢复数据库,只支持MyISAM引擎;
2、如果有数据库或数据表使用了InnoDB引擎,恢复的时候,必须连同MySQL数据库目录下的ibdata1文件一起拷贝过来。
解决办法:
1、停止MySQL服务
service mysqld stop
2、找之前的备份数据库文件
cd /home/mysql_bak/mysql/ #进入MySQL备份目录
ibdata1 #需要此文件
3、拷贝ibdata1文件到数据库相应目录
cp /home/mysql_bak/mysql/ibdata1 /usr/local/mysql/data/ibdata1 #拷贝文件到现在的数据库目录
chown mysql.mysql /usr/local/mysql/data/ibdata1 #设置权限位mysql用户和用户组
rm /usr/local/mysql/data/ib_logfile0 #删除现有日志文件,否则启动MySQL失败
rm /usr/local/mysql/data/ib_logfile1 #删除现有日志文件,否则启动MySQL失败
4、启动MySQL
service mysqld start
故障解决
此时页面已正常打开。
ibdata1作用:InnoDB引擎下的表数据文件。
建议:数据库一定要做好备份,恢复数据最好使用.sql备份文件导入。
至此,MySQL数据库InnoDB引擎下服务器断电数据恢复教程完成。
以上就是MySQL数据库InnoDB引擎下服务器断电数据恢复方法_MySQL的内容,更多相关内容请关注PHP中文网(www.php.cn)!

ACID attributes include atomicity, consistency, isolation and durability, and are the cornerstone of database design. 1. Atomicity ensures that the transaction is either completely successful or completely failed. 2. Consistency ensures that the database remains consistent before and after a transaction. 3. Isolation ensures that transactions do not interfere with each other. 4. Persistence ensures that data is permanently saved after transaction submission.

MySQL is not only a database management system (DBMS) but also closely related to programming languages. 1) As a DBMS, MySQL is used to store, organize and retrieve data, and optimizing indexes can improve query performance. 2) Combining SQL with programming languages, embedded in Python, using ORM tools such as SQLAlchemy can simplify operations. 3) Performance optimization includes indexing, querying, caching, library and table division and transaction management.

MySQL uses SQL commands to manage data. 1. Basic commands include SELECT, INSERT, UPDATE and DELETE. 2. Advanced usage involves JOIN, subquery and aggregate functions. 3. Common errors include syntax, logic and performance issues. 4. Optimization tips include using indexes, avoiding SELECT* and using LIMIT.

MySQL is an efficient relational database management system suitable for storing and managing data. Its advantages include high-performance queries, flexible transaction processing and rich data types. In practical applications, MySQL is often used in e-commerce platforms, social networks and content management systems, but attention should be paid to performance optimization, data security and scalability.

The relationship between SQL and MySQL is the relationship between standard languages and specific implementations. 1.SQL is a standard language used to manage and operate relational databases, allowing data addition, deletion, modification and query. 2.MySQL is a specific database management system that uses SQL as its operating language and provides efficient data storage and management.

InnoDB uses redologs and undologs to ensure data consistency and reliability. 1.redologs record data page modification to ensure crash recovery and transaction persistence. 2.undologs records the original data value and supports transaction rollback and MVCC.

Key metrics for EXPLAIN commands include type, key, rows, and Extra. 1) The type reflects the access type of the query. The higher the value, the higher the efficiency, such as const is better than ALL. 2) The key displays the index used, and NULL indicates no index. 3) rows estimates the number of scanned rows, affecting query performance. 4) Extra provides additional information, such as Usingfilesort prompts that it needs to be optimized.

Usingtemporary indicates that the need to create temporary tables in MySQL queries, which are commonly found in ORDERBY using DISTINCT, GROUPBY, or non-indexed columns. You can avoid the occurrence of indexes and rewrite queries and improve query performance. Specifically, when Usingtemporary appears in EXPLAIN output, it means that MySQL needs to create temporary tables to handle queries. This usually occurs when: 1) deduplication or grouping when using DISTINCT or GROUPBY; 2) sort when ORDERBY contains non-index columns; 3) use complex subquery or join operations. Optimization methods include: 1) ORDERBY and GROUPB


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

Atom editor mac version download
The most popular open source editor

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function

Dreamweaver Mac version
Visual web development tools

Notepad++7.3.1
Easy-to-use and free code editor