我可以运行这个查询来获得MySQL数据库中所有表的大小:

show table status from myDatabaseName;

我希望有人能帮助我理解结果。我在找尺寸最大的桌子。

我应该看哪一列?


当前回答

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;

其他回答

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;

最后计算数据库的总大小:

(SELECT 
  table_name AS `Table`, 
  round(((data_length + index_length) / 1024 / 1024), 2) `Size in MB` 
  FROM information_schema.TABLES 
  WHERE table_schema = "$DB_NAME"
)
UNION ALL
(SELECT 
  'TOTAL:',
  SUM(round(((data_length + index_length) / 1024 / 1024), 2) )
  FROM information_schema.TABLES 
  WHERE table_schema = "$DB_NAME"
)
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;

下面是另一种使用bash命令行的方法。

for i in `mysql -NB -e 'show databases'`; do echo $i; mysql -e "SELECT table_name AS 'Tables', round(((data_length+index_length)/1024/1024),2) 'Size in MB' FROM information_schema.TABLES WHERE table_schema =\"$i\" ORDER BY (data_length + index_length) DESC" ; done

这只是一个供以后参考的说明。所有答案都依赖于I_S.TABLES。例如,如果你在表中有blob字段,它不会告诉你正确的大小。LOB页存储在外部页中,因此不计入聚集索引。 事实上有一个注释:

对于NDB表,该语句的输出显示适当的值 AVG_ROW_LENGTH和DATA_LENGTH列,例外 没有考虑到BLOB列。

我发现InnoDB也是如此。

我已经创建了社区Bug相同。