查询所有数据库占用磁盘空间大小的SQL语句: 语句如下: select TABLE_SCHEMA, concat(truncate(sum(data_length)/1024/1024,2),' MB') as data_size, concat(truncate(sum(index_length)/1024/1024,2),'MB') as index_size from information_schema.tables group by TABLE_SCHEMA order by data
1:show databases; 查看所有的数据库,等同于select schema_name from information_schema.schemata\G.\G 替换;,以纵向报表的形式输出结果,有利于阅读. 2. status 查看mysql数据库的运行状态 3. use 命令选择数据库 例如 use information_schema,当使用此命令后 select schema_name from information_schema.schemata\G,可以为 select
查看索引: select * FROM information_schema.TABLE_CONSTRAINTS ; select * FROM information_schema.TABLE_CONSTRAINTS WHERE TABLE_NAME=‘table_name’ ; 查看表信息: show create table table_name; 查看触发器: SELECT * FROM information_schema.`TRIGGERS`;
查询所有数据库占用磁盘空间大小的SQL语句: 语句如下 1 2 3 4 5 select TABLE_SCHEMA, concat(truncate(sum(data_length)/1024/1024,2),' MB') as data_size, concat(truncate(sum(index_length)/1024/1024,2),'MB') as index_size from information_schema.tables group by TABLE_SCHEMA orde
查询所有数据库占用磁盘空间大小的SQL语句: 语句如下 select TABLE_SCHEMA, concat(truncate(sum(data_length)/1024/1024,2),' MB') as data_size, concat(truncate(sum(index_length)/1024/1024,2),'MB') as index_size from information_schema.tables group by TABLE_SCHEMA order by data_
SELECT TABLE_NAME,DATA_LENGTH+INDEX_LENGTH,TABLE_ROWS FROM information_schema.tables WHERE TABLE_SCHEMA='price_clouds' AND TABLE_NAME='t_match_task_content';
MySQL5.6中引入了MRR,专门来优化:二级索引的范围扫描并且需要回表的情况.它的原理是,将多个需要回表的二级索引根据主键进行排序,然后一起回表,将原来的回表时进行的随机IO,转变成顺序IO.文档地址:http://dev.mysql.com/doc/refman/5.6/en/mrr-optimization.html Reading rows using a range scan on a secondary index can result in many random disk ac
一.一探究竟 我想看看有多少个数据库,有多少个表,以及表里有啥东西.那么你可以这样: 图形界面: 命令: 查看多少个数据库:注意 后面带s #查看 SHOW DATABASES; #查看表 USE blog; SHOW TABLES; #查看表中的列 SHOW COLUMNS FROM auth_user; DESCRIBE auth_user; describe 表名 是 show columns from 表名 的一种快捷方式. 二.修改mysql数据库密码 方法一: 使用phpmyadmi
mysql查看被锁的进程 //查看所有进程show processlist; //查询是否锁表show OPEN TABLES where In_use > 0; //查看被锁住的 SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCKS; //等待锁定 SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCK_WAITS;
mysql查看表结构命令,如下: desc 表名; show columns from 表名; describe 表名; show create table 表名; use information_schema select * from columns where table_name='表名'; 顺便记下: show databases; use 数据库名; show tables; 原有一unique索引AK_PAS_Name(PAC_Name)在表tb_webparamcounter中,
查看所有库的大小 mysql> use information_schema; Database changed mysql> selectconcat(round(sum(DATA_LENGTH/1024/1024),2),'MB') as data from TABLES; +----------+ | data | +----------+ | 104.21MB | +----------+ 1 row in set (0.11 sec) 查看指定库的大小 mysql> s