MySQL分析步 - 技术栈

MySQL分析

sql 复制代码
-- 库名
set @dbName = 'bsa_crmeb_bak';
-- 表名
set @tableName = 'bsa_crmeb_bak';

-- 查看bsa_crmeb_bak数据库基本信息
SELECT
    SCHEMA_NAME AS '数据库名',
    DEFAULT_CHARACTER_SET_NAME AS '字符集',
    DEFAULT_COLLATION_NAME AS '排序规则'
FROM information_schema.SCHEMATA
WHERE SCHEMA_NAME = @dbName;

-- 查看数据库中所有表的信息
SELECT
    TABLE_NAME AS '表名',
    TABLE_ROWS AS '预估记录数',
    DATA_LENGTH/1024/1024 AS '数据大小(MB)',
    INDEX_LENGTH/1024/1024 AS '索引大小(MB)',
    (DATA_LENGTH + INDEX_LENGTH)/1024/1024 AS '总大小(MB)',
    (DATA_LENGTH + INDEX_LENGTH)/1024/1024/1024 AS '总大小(GB)',
    TABLE_COMMENT AS '表注释'
FROM information_schema.TABLES
WHERE TABLE_SCHEMA = @dbName
ORDER BY (DATA_LENGTH + INDEX_LENGTH) DESC;

-- 重新计算表的统计信息
ANALYZE TABLE @tableName;

-- 查看数据库中所有表的信息
SELECT
    TABLE_NAME AS '表名',
    TABLE_ROWS AS '预估记录数',
    DATA_LENGTH/1024/1024 AS '数据大小(MB)',
    INDEX_LENGTH/1024/1024 AS '索引大小(MB)',
    (DATA_LENGTH + INDEX_LENGTH)/1024/1024 AS '总大小(MB)',
    sum((DATA_LENGTH + INDEX_LENGTH)/1024/1024/1024) AS '总大小(GB)',
    TABLE_COMMENT AS '表注释'
FROM information_schema.TABLES
WHERE TABLE_SCHEMA = @dbName
ORDER BY (DATA_LENGTH + INDEX_LENGTH) DESC;

-- 查看特定表的字段结构
SELECT
    COLUMN_NAME AS '字段名',
    COLUMN_TYPE AS '数据类型',
    IS_NULLABLE AS '是否可空',
    COLUMN_DEFAULT AS '默认值',
    COLUMN_COMMENT AS '字段说明',
    COLUMN_KEY AS '索引信息'
FROM information_schema.COLUMNS
WHERE TABLE_SCHEMA = @dbName
  AND TABLE_NAME = @tableName
ORDER BY ORDINAL_POSITION;

-- 查看表中数据的基本统计信息（以用户为例）
SELECT
    COUNT(*) AS 总记录数,
    COUNT(DISTINCT user_id) AS 唯一用户数,
    MIN(create_time) AS 最早创建时间,
    MAX(create_time) AS 最新创建时间
FROM @tableName;

-- 查看表中数据的基本统计信息（以1655用户为例）
SELECT
    COUNT(*) AS 总记录数,
    COUNT(DISTINCT user_id) AS 唯一用户数,
    MIN(create_time) AS 最早创建时间,
    MAX(create_time) AS 最新创建时间
FROM @tableName where user_id = 1655;

-- 查看数据分布情况
SELECT
    user_id,
    COUNT(*) as 数量,
    ROUND(COUNT(*) * 100.0 / (SELECT COUNT(*) FROM @tableName), 2) as 百分比
FROM @tableName
GROUP BY user_id
ORDER BY 数量 DESC;

-- 查看表的索引信息
SHOW INDEX FROM @tableName;

-- 或者通过information_schema查询
SELECT
    INDEX_NAME AS '索引名',
    COLUMN_NAME AS '字段名',
    NON_UNIQUE AS '是否非唯一',
    SEQ_IN_INDEX AS '索引顺序',
    INDEX_TYPE AS '索引类型'
FROM information_schema.STATISTICS
WHERE TABLE_SCHEMA = @dbName
AND TABLE_NAME = @tableName
ORDER BY INDEX_NAME, SEQ_IN_INDEX;

-- 开启查询分析
SET profiling = 1;

-- 执行你的查询语句
SELECT * FROM @tableName WHERE user_id = 1655;

-- 查看查询分析结果
SHOW PROFILES;
SHOW PROFILE FOR QUERY 1; -- 查看第一个查询的详细信息

-- 查看当前数据库连接状态
SHOW STATUS LIKE 'Threads_connected';
SHOW STATUS LIKE 'Threads_running';

-- 查看数据库最大连接数设置
SHOW VARIABLES LIKE 'max_connections';

-- 查看慢查询相关设置
SHOW VARIABLES LIKE 'slow_query_log';
SHOW VARIABLES LIKE 'long_query_time';

-- 查看表使用的存储引擎
SELECT
    TABLE_NAME,
    ENGINE,
    TABLE_ROWS,
    DATA_LENGTH/1024/1024 AS '数据大小(MB)'
FROM information_schema.TABLES
WHERE TABLE_SCHEMA = @dbName
ORDER BY DATA_LENGTH DESC;

-- 查看数据库中的外键关系
SELECT
    TABLE_NAME AS '表名',
    COLUMN_NAME AS '字段名',
    CONSTRAINT_NAME AS '约束名',
    REFERENCED_TABLE_NAME AS '引用表',
    REFERENCED_COLUMN_NAME AS '引用字段'
FROM information_schema.KEY_COLUMN_USAGE
WHERE TABLE_SCHEMA = @dbName
AND REFERENCED_TABLE_NAME IS NOT NULL
ORDER BY TABLE_NAME;

-- 查看数据库中的视图
SELECT
    TABLE_NAME AS '视图名',
    VIEW_DEFINITION AS '视图定义'
FROM information_schema.VIEWS
WHERE TABLE_SCHEMA = @dbName;

-- 查看存储过程和函数
SELECT
    ROUTINE_NAME AS '名称',
    ROUTINE_TYPE AS '类型',
    CREATED AS '创建时间',
    LAST_ALTERED AS '最后修改时间'
FROM information_schema.ROUTINES
WHERE ROUTINE_SCHEMA = @dbName;

-- 查看数据库相关的性能参数
SHOW VARIABLES LIKE '%buffer_pool%';
SHOW VARIABLES LIKE '%innodb%';
SHOW STATUS LIKE '%innodb%';