【推荐】单表行数超过 500 万行或者单表容量超过 2GB，才推荐进行分库分表。
说明：如果预计三年后的数据量根本达不到这个级别，请不要在创建表时就分库分表。

1. 查询所有数据库记录数和容量

SELECT
	table_schema AS '数据库',
	SUM(table_rows) AS '记录数',
	SUM(TRUNCATE(data_length/1024/1024, 2)) AS '数据容量(MB)',
	SUM(TRUNCATE(index_length/1024/1024, 2)) AS '索引容量(MB)'
FROM information_schema.tables
GROUP BY table_schema
ORDER BY SUM(data_length) DESC, SUM(index_length) DESC;

2. 查询指定数据库记录数和容量

SELECT
	table_schema AS '数据库',
	SUM( table_rows ) AS '记录数',
	SUM(TRUNCATE ( data_length / 1024 / 1024, 2 )) AS '数据容量(MB)',
	SUM(TRUNCATE ( index_length / 1024 / 1024, 2 )) AS '索引容量(MB)' 
FROM information_schema.TABLES 
WHERE table_schema = 'syspt';

3、查询所有数据库每个表的记录数和容量

SELECT
	table_schema AS '数据库',
	table_name AS '表名',
	table_rows AS '记录数',
	TRUNCATE(data_length/1024/1024, 2) AS '数据容量(MB)',
	TRUNCATE(index_length/1024/1024, 2) AS '索引容量(MB)'
FROM information_schema.tables
ORDER BY data_length DESC, index_length DESC;

4. 查询指定数据库每个表的记录数和容量

SELECT
	table_schema AS '数据库',
	table_name AS '表名',
	table_rows AS '记录数',
	TRUNCATE(data_length/1024/1024, 2) AS '数据容量(MB)',
	TRUNCATE(index_length/1024/1024, 2) AS '索引容量(MB)'
FROM information_schema.tables
WHERE table_schema='syspt'
ORDER BY data_length DESC, index_length DESC;

5. 统计所有数据库的总大小

SELECT CONCAT(ROUND(SUM(DATA_LENGTH/1024/1024),2),'MB') AS DATA FROM information_schema.TABLES;