参考原文: https://www.cnblogs.com/chuanzhang053/p/16937461.html

查看每个库中表的大小，按大小排序

注意：表占用空间大小，包括 数据 和 索引

SELECT
     table_schema as `Database`,
     table_name AS `Table`,
     round(((data_length + index_length) / 1024 / 1024), 2) `Size in MB`
FROM information_schema.TABLES
ORDER BY (data_length + index_length) DESC;

查看某个特定的库中，表的大小

SELECT
     table_schema as `Database`,
     table_name AS `Table`,
     round(((data_length + index_length) / 1024 / 1024), 2) `Size in MB`
FROM information_schema.TABLES
WHERE table_schema = "iuap_data_datafusion"  # 替换为具体的库名
ORDER BY (data_length + index_length) DESC;