MySQL--查询表统计信息

可以用show table status 来查看表的信息，如:

show table status like '%waybill5%' \G

但使用information_schema.`TABLES`更方便查看。

 

查看数据库级别的使用情况

SELECT 
TABLE_SCHEMA AS database_name,
SUM(ROUND((DATA_LENGTH+INDEX_LENGTH+DATA_FREE)/1024.0/1024, 2)) AS Total_MB
FROM information_schema.`TABLES` AS T1
WHERE T1.`TABLE_SCHEMA` NOT IN('performance_schema','mysql','information_schema')
GROUP BY T1.`TABLE_SCHEMA`
ORDER BY SUM(ROUND((DATA_LENGTH+INDEX_LENGTH+DATA_FREE)/1024.0/1024, 2)) DESC
LIMIT 10;

 

查看非InnoDB引擎表

## 查看非InnoDB引擎表
SELECT 
TABLE_SCHEMA AS database_name,
TABLE_NAME AS table_name,
TABLE_ROWS AS table_rows,
ENGINE AS table_engine,
ROUND((DATA_LENGTH)/1024.0/1024, 2) AS Data_MB,
ROUND((INDEX_LENGTH)/1024.0/1024, 2) AS Index_MB,
ROUND((DATA_LENGTH+INDEX_LENGTH)/1024.0/1024, 2) AS Total_MB,
ROUND((DATA_FREE)/1024.0/1024, 2) AS Free_MB
FROM information_schema.`TABLES` AS T1
WHERE T1.`TABLE_SCHEMA` NOT IN('performance_schema','mysql','information_schema','sys')
AND T1.`ENGINE` NOT IN ('innodb');

 

查看数据表较大的表

## 查看数据表量较大的表
SELECT 
TABLE_SCHEMA AS database_name,
TABLE_NAME AS table_name,
TABLE_ROWS AS table_rows,
ENGINE AS table_engine,
ROUND((DATA_LENGTH)/1024.0/1024, 2) AS Data_MB,
ROUND((INDEX_LENGTH)/1024.0/1024, 2) AS Index_MB,
ROUND((DATA_FREE)/1024.0/1024, 2) AS Free_MB,
ROUND((DATA_LENGTH+INDEX_LENGTH+DATA_FREE)/1024.0/1024, 2) AS Total_MB
FROM information_schema.`TABLES` AS T1
WHERE T1.`TABLE_SCHEMA` NOT IN('performance_schema','mysql','information_schema')
ORDER BY T1.`TABLE_ROWS` DESC
LIMIT 10;

## 查看存储空间较大的表
SELECT 
TABLE_SCHEMA AS database_name,
TABLE_NAME AS table_name,
TABLE_ROWS AS table_rows,
ENGINE AS table_engine,
ROUND((DATA_LENGTH)/1024.0/1024, 2) AS Data_MB,
ROUND((INDEX_LENGTH)/1024.0/1024, 2) AS Index_MB,
ROUND((DATA_FREE)/1024.0/1024, 2) AS Free_MB,
ROUND((DATA_LENGTH+INDEX_LENGTH+DATA_FREE)/1024.0/1024, 2) AS Total_MB
FROM information_schema.`TABLES` AS T1
WHERE T1.`TABLE_SCHEMA` NOT IN('performance_schema','mysql','information_schema')
ORDER BY ROUND((DATA_LENGTH+INDEX_LENGTH+DATA_FREE)/1024.0/1024, 2) DESC
LIMIT 10;

 

查看碎片较多的表

## 查看碎片较多的表
SELECT 
TABLE_SCHEMA AS database_name,
TABLE_NAME AS table_name,
TABLE_ROWS AS table_rows,
ENGINE AS table_engine,
ROUND((DATA_LENGTH)/1024.0/1024, 2) AS Data_MB,
ROUND((INDEX_LENGTH)/1024.0/1024, 2) AS Index_MB,
ROUND((DATA_FREE)/1024.0/1024, 2) AS Free_MB,
ROUND((DATA_LENGTH+INDEX_LENGTH+DATA_FREE)/1024.0/1024, 2) AS Total_MB,
ROUND(ROUND((DATA_FREE)/1024.0/1024, 2) /ROUND((DATA_LENGTH+INDEX_LENGTH)/1024.0/1024, 2)*100,2)AS Free_Percent
FROM information_schema.`TABLES` AS T1
WHERE T1.`TABLE_SCHEMA` NOT IN('performance_schema','mysql','information_schema')
AND ROUND(ROUND((DATA_FREE)/1024.0/1024, 2) /ROUND((DATA_LENGTH+INDEX_LENGTH)/1024.0/1024, 2)*100,2) >5
AND ROUND((DATA_FREE)/1024.0/1024, 2)>10
ORDER BY ROUND((DATA_FREE)/1024.0/1024, 2) DESC
LIMIT 10;

 

查看表当前自增值

## 查看表自增值
SELECT 
T2.TABLE_SCHEMA,
T2.TABLE_NAME, 
T1.COLUMN_NAME,
T1.COLUMN_TYPE,
T2.AUTO_INCREMENT
FROM information_schema.columns AS T1
INNER JOIN information_schema.tables AS T2
ON T1.TABLE_SCHEMA=T2.TABLE_SCHEMA
AND T1.TABLE_NAME=T2.TABLE_NAME
WHERE T1.EXTRA='auto_increment'
AND T1.DATA_TYPE NOT LIKE '%bigint%'
ORDER BY T2.AUTO_INCREMENT DESC
LIMIT 100;

 

查看无主键表

## 查看无主键表
SELECT
TABLE_SCHEMA AS database_name,
TABLE_NAME AS table_name,
TABLE_ROWS AS table_rows,
ENGINE AS table_engine,
ROUND((DATA_LENGTH)/1024.0/1024, 2) AS Data_MB,
ROUND((INDEX_LENGTH)/1024.0/1024, 2) AS Index_MB,
ROUND((DATA_LENGTH+INDEX_LENGTH)/1024.0/1024, 2) AS Total_MB,
ROUND((DATA_FREE)/1024.0/1024, 2) AS Free_MB
FROM information_schema.tables
WHERE (table_schema, table_name) NOT IN (
SELECT DISTINCT table_schema, table_name
FROM information_schema.columns
WHERE COLUMN_KEY = 'PRI'
)
AND table_schema NOT IN ('sys', 'mysql', 'information_schema', 'performance_schema');

 

查看UTF8/UTF8MB4的表

## 查看使用utf8mb4字符集表
SELECT 
T1.TABLE_SCHEMA,
T1.TABLE_NAME,
T1.TABLE_TYPE,
T1.TABLE_ROWS,
T1.TABLE_COMMENT,
T1.TABLE_COLLATION,
CONCAT( 'ALTER TABLE `', TABLE_SCHEMA, '`.`', TABLE_NAME,
'` CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;' ) AS CHANGE_SQL
FROM information_schema.TABLES T1
WHERE T1.TABLE_SCHEMA NOT IN('sys','performance_schema','information_schema','mysql') 
AND T1.TABLE_COLLATION LIKE 'utf8mb4%'
ORDER BY T1.TABLE_ROWS DESC;


## 查看使用utf8字符集但应使用utf8mb4字符集的表
SELECT 
T1.TABLE_SCHEMA,
T1.TABLE_NAME,
T1.TABLE_TYPE,
T1.TABLE_ROWS,
T1.TABLE_COMMENT,
T1.TABLE_COLLATION,
CONCAT( 'ALTER TABLE `', TABLE_SCHEMA, '`.`', TABLE_NAME,
'` CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;' ) AS CHANGE_SQL
FROM information_schema.TABLES T1
WHERE T1.TABLE_SCHEMA NOT IN('sys','performance_schema','information_schema','mysql') 
AND T1.TABLE_COLLATION LIKE 'utf8%'
AND T1.TABLE_COLLATION NOT LIKE 'utf8mb4%'
ORDER BY T1.TABLE_ROWS DESC;


## 查看使用utf8mb4字符集但未使用utf8mb4_general_ci排序规则的表
SELECT 
T1.TABLE_SCHEMA,
T1.TABLE_NAME,
T1.TABLE_TYPE,
T1.TABLE_ROWS,
T1.TABLE_COMMENT,
T1.TABLE_COLLATION,
CONCAT( 'ALTER TABLE `', TABLE_SCHEMA, '`.`', TABLE_NAME,
'` CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;' ) AS CHANGE_SQL
FROM information_schema.TABLES T1
WHERE T1.TABLE_SCHEMA NOT IN('sys','performance_schema','information_schema','mysql') 
AND T1.TABLE_COLLATION<>'utf8mb4_general_ci'
AND T1.TABLE_COLLATION LIKE 'utf8mb4_%'
ORDER BY T1.TABLE_ROWS DESC;