当MySQL必须要进行排序时，就会在从磁盘上读取数据时分配一个排序缓冲区来存放这些数据行。

When MySQL must perform a sort, it allocates a sort buffer to store the rows as they're read from disk.

youdao

当MySQL必须要进行排序时，就会在从磁盘上读取数据时分配一个排序缓冲区来存放这些数据行。

When MySQL must perform a sort, it allocates a sort buffer to store the rows as they're read from disk.

youdao