mysql - Optimizing existing tables by changing data types

Question

Lets say i have a table with 10,000 rows and one of the columns is of type INT and unsigned. If i alter the column to be of type SMALLINT and unsigned will it shrink the space the existing data takes on the disk? or only future inserts?

Answer 1

你为什么不试试看呢？获得自己的经验数据很容易。

你认为你会节省多少空间？您将一个 4 字节的 INT 更改为 2 字节的 SMALLINT，您将节省两个字节，即整个表的 20K。你有那么硬的磁盘空间吗？