MySQL配置文件路径及‘The total number of locks exceeds the l_MySQL
在删除mysql中的数据时,遇到报错:
ERROR 1206 (HY000): The total number of locks exceeds the lock table size
查了查,发现是mysql配置里 innodb_buffer_pool_size 这一个配置太小造成InnoDB在执行大批量数据的插入、删除时会无法执行,检查配置:
mysql> show variables like '%_buffer%';+-------------------------+---------+| Variable_name | Value |+-------------------------+---------+| bulk_insert_buffer_size | 8388608 || innodb_buffer_pool_size | 8388608 |
innodb_buffer_pool_size才8M,无语中,OP给配的果然不靠谱,设成256M,重启MySQL
innodb_buffer_pool_size = 256M
然后再检查配置项,发现innodb_buffer_pool_size 依然是8M,感觉很离奇,然后想到是不是配置文件没有生效,所以检查mysql引用的配置文件位置
执行
/home/mysql/bin/mysqld --verbose --help | grep -A 1 'Default options'
结果为
Default options are read from the following files in the given order:/etc/my.cnf /etc/mysql/my.cnf /home/mysql/etc/my.cnf ~/.my.cnf
逐个检查my.cnf,发现根本就没对应的文件,OP给配的果然不靠谱。。
把my.cnf复制到 /home/mysql/etc/ 路径下,重启mysql,检查InnoDB变量
mysql> show variables like '%_buffer%';+-------------------------+-----------+| Variable_name | Value |+-------------------------+-----------+| bulk_insert_buffer_size | 8388608 || innodb_buffer_pool_size | 268435456 |...
配置生效,然后再执行之前的delete操作,删除OK

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MySQL is suitable for beginners because: 1) easy to install and configure, 2) rich learning resources, 3) intuitive SQL syntax, 4) powerful tool support. Nevertheless, beginners need to overcome challenges such as database design, query optimization, security management, and data backup.

Yes,SQLisaprogramminglanguagespecializedfordatamanagement.1)It'sdeclarative,focusingonwhattoachieveratherthanhow.2)SQLisessentialforquerying,inserting,updating,anddeletingdatainrelationaldatabases.3)Whileuser-friendly,itrequiresoptimizationtoavoidper

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.


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