Note that if several counting functions or tests operate on the same column, then the sort and count operations only need to be done once.

注意，如果多个计数函数或测试在同一列上运行，那么排序与计数操作仅需做一次。

youdao

Note that if several counting functions or tests operate on the same column, then the sort and count operations only need to be done once.

注意，如果多个计数函数或测试在同一列上运行，那么排序与计数操作仅需做一次。

youdao