mysql> SHOW GLOBAL STATUS LIKE 'Innodb_buffer_pool_pages_data'; +-------------------------------+-------+ | Variable_name | Value | +-------------------------------+-------+ | Innodb_buffer_pool_pages_data | 138
SET @myVariable = 10; 应用场景: 在存储过程或函数中传递参数。 在复杂查询中存储中间结果。 2. 修改系统变量 SET也可以用于修改MySQL的系统变量。 示例: 代码语言:txt 复制 SET GLOBAL innodb_buffer_pool_size = 2147483648; 优势: 可以动态调整数据库配置,无需重启MySQL服务。
SETGLOBALinnodb_buffer_pool_size=2*1024*1024*1024; 1. 通过上述语句,我们成功地设置了innodb_buffer_pool_size的值为2GB,这将影响数据库的性能和缓冲区的大小。 类图 下面是一个简单的类图,展示了系统变量mysql的相关类和属性: SystemVariable+name : String+value : String+description : String+set(value: ...
-- 设置系统变量 SET GLOBAL innodb_buffer_pool_size = 2147483648; -- 设置用户定义变量 SET @my_variable = 'Hello, World!'; -- 使用用户定义变量 SELECT CONCAT('Welcome to ', @my_variable); 参考链接 MySQL Documentation - SET Syntax MySQL Documentation - System Variables 常见问题及解决方法 问题...
SET GLOBAL命令的作用是改变全局系统变量的值,这些变量对于所有的MySQL会话都是可见的,并且更改立即生效,除非该变量被设计为需要重启服务器才能生效,这意味着你可以实时调整MySQL服务器的行为,而无需重启服务。 使用场景 1、性能优化调整如innodb_buffer_pool_size或query_cache_size这样的内存相关变量来优化MySQL的性能...
1. InnoDB Adaptive hash Index This variable is enabled by default.The feature known as the adaptive hash index (AHI) lets InnoDB perform more like an in-memory database on systems with appropriate combinations of workload and ample memory for the buffer pool, without sacrificing any transactional...
innodb_buffer_pool_size: This setting determines the amount of memory allocated to the InnoDB buffer pool, which caches frequently accessed data for faster retrieval. Increasing this value can improve performance for read-heavy workloads, but it also consumes more memory. query_cache_size: This set...
Description:SET PERSISTS does not work as described IMHO and behaves a bit random...How to repeat:mysql> show global variables like 'innodb_buffer_pool_size'; +---+---+ | Variable_name | Value | +---+---+ | innodb_buffer_pool_size | 134217728 | +---+---+ mysql> set persist...
(0.00 sec) mysql> show global variables like 'innodb_buffer_pool_size%'; +---+---+ | Variable_name | Value | +---+---+ | innodb_buffer_pool_size | 356515840 | +---+---+ 1 row in set (0.00 sec) mysql> mysql> SELECT * FROM information_schema.GLOBAL_VARIABLES WHERE VARIABLE...
SETcharacter_set_client=gbkSETcharacter_set_results=gbk--而SETcharacter_set_connection=utf8 这样数据在 MySQL内部的存储表示 为 utf8 字符集,而与 客户端交互时,使用gbk字符集合 ref:谈谈MySQL乱码和set names 我个人觉得,由于本地机为gbk编码,所以,即使创建数据库时的编码是utf8,当我们录入数据时,仍然需要...