select x.dbname as db_name, x.table_name as table_name, x.bytesize as the_size from
  (select
     table_schema as dbname,
     sum(index_length+data_length) as bytesize,
     table_name
   from
     information_schema.tables
   group by table_schema
  ) x
where
  x.bytesize > 999999
order by x.bytesize desc;

SELECT 
    table_name AS "Table",  
    round(((data_length + index_length) / 1024 / 1024), 2) as size   
FROM information_schema.TABLES  
WHERE table_schema = "YOUR_DATABASE_NAME"  
ORDER BY size DESC; 

这将对大小进行排序(DB大小以MB为单位)。

SELECT TABLE_NAME AS "Table Name", 
table_rows AS "Quant of Rows", ROUND( (
data_length + index_length
) /1024, 2 ) AS "Total Size Kb"
FROM information_schema.TABLES
WHERE information_schema.TABLES.table_schema = 'YOUR SCHEMA NAME/DATABASE NAME HERE'
LIMIT 0 , 30

您可以从“information_schema”-> SCHEMATA表->“SCHEMA_NAME”列中获取模式名称

额外的 你可以得到mysql数据库的大小如下。

SELECT table_schema "DB Name", 
Round(Sum(data_length + index_length) / 1024 / 1024, 1) "DB Size in MB" 
FROM   information_schema.tables 
GROUP  BY table_schema
ORDER BY `DB Size in MB` DESC;

结果

DB Name              |      DB Size in MB

mydatabase_wrdp             39.1
information_schema          0.0

你可以在这里得到更多的细节。

你可以使用这个查询来显示表的大小(尽管你需要先替换变量):

SELECT 
    table_name AS `Table`, 
    round(((data_length + index_length) / 1024 / 1024), 2) `Size in MB` 
FROM information_schema.TABLES 
WHERE table_schema = "$DB_NAME"
    AND table_name = "$TABLE_NAME";

或者这个查询列出每个数据库中每个表的大小，最大的先:

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;

另一种显示所占用的行数和空间并按其排序的方法。

SELECT
     table_schema as `Database`,
     table_name AS `Table`,
     table_rows AS "Quant of Rows",
     round(((data_length + index_length) / 1024 / 1024/ 1024), 2) `Size in GB`
FROM information_schema.TABLES
WHERE table_schema = 'yourDatabaseName'
ORDER BY (data_length + index_length) DESC;  

在这个查询中唯一需要替换的字符串是“yourDatabaseName”。

这应该在mysql中测试，而不是postgresql:

SELECT table_schema, # "DB Name", 
Round(Sum(data_length + index_length) / 1024 / 1024, 1) # "DB Size in MB" 
FROM   information_schema.tables 
GROUP  BY table_schema;