它还有助于确定源和目标之间的关系类型，比如聚合、转换和算术运算。

It also helps in types of relationship between source and target, such as aggregations, transformations, and arithmetic operations.

youdao

包括计数和运算技能、识别图式和关系，时间和次序以及运用逻辑解决各种各样问题的能力。

Involves number and computing skills, recognizing patterns and relationships, timeliness and order, and the ability to solve different kinds of problems through logic.

youdao

操作可以是一个关系运算符，或者系统或用户定义的函数，也可以是一个sql操作符，例如GROUP BY、ORDER BY等。

An operation can be a relational operator, a system - or user-defined function, or an SQL operator, such as GROUP BY, ORDER BY, and so on.

youdao

I just want to make mention of this in case there's ever doubt, generally parentheses do solve your problem as an arithmetic but do realize this is some lower level details we'll come back to over time.

是想告诉大家如果你对某些式子的前后运算关系不确定，就加上括号,这都是一些小细节,我们以后还是会再提到的。

哈佛公开课 - 计算机科学课程节选