I don't agree at all that this phenomenon is restricted to database programming. Thinking in terms of higher-level operations is always more readable and often

I don't agree at all that this phenomenon is restricted to database programming. Thinking in terms of higher-level operations is always more readable and often more efficient (the logical conclusion being things like Haksell and Prolog where there aren't really operations at all). For example, to find the common elements in two lists, you could use a for loop, or you could follow the OP's advice and use set operations to do something like: set(list1).intersection(set(list2))