centos7 在线安装mysql5.7部分5

[hx@localhost 桌面]$ sudo yum install -y https://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm

[hx@localhost 桌面]$ sudo rpm --import https://repo.mysql.com/RPM-GPG-KEY-mysql

[hx@localhost 桌面]$ sudo yum install -y mysql-community-server

上述失败
wget https://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm
sudo rpm -ivh mysql57-community-release-el7-11.noarch.rpm

手动安装 MySQL 组件
sudo yum install mysql-community-server --nogpgcheck

sudo yum install mysql-community-server --nogpgcheck

验证是否安装成功
sudo systemctl start mysqld
sudo systemctl status mysqld

获取临时密码
sudo grep 'temporary password' /var/log/mysqld.log

[hx@localhost 桌面]$ sudo grep 'temporary password' /var/log/mysqld.log
2025-07-30T06:33:30.679287Z 1 [Note] A temporary password is generated for root@localhost: %JRjcevgK65k
[hx@localhost 桌面]$
%JRjcevgK65k
%JRjcevgK65k
ALTER USER 'root'@'localhost' IDENTIFIED BY 'Root@1234';

mysql> select version();
+-----------+
| version() |
+-----------+
| 5.7.44    |
+-----------+
1 row in set (0.00 sec)

运维部分sql信息

1. 查询所有数据库占用空间
SELECT 
    table_schema AS '数据库名',
    ROUND(SUM(data_length + index_length) / 1024 / 1024, 2) AS '总大小(MB)',
    ROUND(SUM(data_length) / 1024 / 1024, 2) AS '数据大小(MB)',
    ROUND(SUM(index_length) / 1024 / 1024, 2) AS '索引大小(MB)'
FROM 
    information_schema.tables
GROUP BY 
    table_schema
ORDER BY 
    SUM(data_length + index_length) DESC;

2. 查询单个数据库中各表占用空间
SELECT 
    table_name AS '表名',
    ROUND(data_length / 1024 / 1024, 2) AS '数据大小(MB)',
    ROUND(index_length / 1024 / 1024, 2) AS '索引大小(MB)',
    ROUND((data_length + index_length) / 1024 / 1024, 2) AS '总大小(MB)',
    table_rows AS '行数'
FROM 
    information_schema.tables
WHERE 
    table_schema = 'mysql'
ORDER BY 
    (data_length + index_length) DESC;

3. 查询数据目录物理文件大小（操作系统命令）
# 查看MySQL数据目录总大小
du -sh /var/lib/mysql/

# 查看各数据库目录大小
du -sh /var/lib/mysql/*

# 查看特定数据库文件大小
du -sh /var/lib/mysql/数据库名/*

4. 查询InnoDB表空间使用情况
SELECT 
    NAME AS '文件',
    ROUND(SUM(ALLOCATED_SIZE)/1024/1024, 2) AS '分配空间(MB)',
    ROUND(SUM(FILE_SIZE)/1024/1024, 2) AS '数据空间(MB)'
FROM 
    information_schema.INNODB_SYS_TABLESPACES
GROUP BY 
    NAME;

5. 查询二进制日志占用空间
SHOW BINARY LOGS;

6. 查询临时文件占用空间
SHOW VARIABLES LIKE 'tmpdir';