mysqldump命令创建的是逻辑备份,结果集有两种格式:一种是将数据转换成标准的SQL语句(一堆CREATE,DROP,INSERT等语句),另一种是
mysqldump命令创建的是逻辑备份,结果集有两种格式:一种是将数据转换成标准的SQL语句(一堆CREATE,DROP,INSERT等语句),另一种是将数据按照指定分隔符,输出成定界格式的平面文件。
[mysql@mysql1 ~]$ mysqldump
usage: mysqldump [OPTIONS] database [tables]
OR mysqldump [OPTIONS] --databases [OPTIONS] DB1 [DB2 DB3...]
OR mysqldump [OPTIONS] --all-databases [OPTIONS]
For more options, use mysqldump –help
[mysql@mysql1 ~]$ mysqldump -usystem -p123456 -S /data/mysqldata/3306/mysql.sock mysql > /data/mysqldata/backup/mysql_fullbak.sql
[mysql@mysql1 ~]$ mysqldump -usystem -p123456 -S /data/mysqldata/3306/mysql.sock --databases mysql test > /data/mysqldata/backup/mysql_test_fullbak.sql
[mysql@mysql1 ~]$ mysqldump -usystem -p123456 -S /data/mysqldata/3306/mysql.sock --all-databases > /data/mysqldata/backup/all_fullbak.sql
输出定界格式文件:当以定界格式进行输出时,mysqldump输出信息默认就不再是标准输出,而是根据对象,每个对象生成对应的两个同名文件,其中一个用于存储对象中的实际数据,文件扩展名为.txt,另一个存储对象的机构(即create table语句),文件扩展名为.sql,这类文件均保存在--tab参数指定的路径下,,默认输出的.txt每条记录输出到一行,行与行之间使用默认的换行符
[mysql@mysql1 ~]$ mysqldump -usystem -p123456 -S /data/mysqldata/3306/mysql.sock --tab=/data/mysqldata/backup mysql
在5.6中执行如下操作
在my.cnf文件中添加
[mysqldump]
user=system
password=123456
[mysql@mysql1 ~]$ mysqldump -S /data/mysqldata/3306/mysql.sock mysql > /data/mysqldata/backup/mysql_fullbak.sql
[mysql@mysql1 ~]$ mysqldump -S /data/mysqldata/3306/mysql.sock --tab=/data/mysqldata/backup mysql
本文永久更新链接地址:

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


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