SAS中的合并与设置语句

Question

I am wondering if there is any difference between merge and set statements in SAS when using only 1 dataset as source.

For example:

 data newdata;
 set olddata;
 run;

vs

data newdata;
merge olddata;
by identifier;
run;

I cant find any differences in the resulting datasets from each method.

Is there any difference between the two statements in a situation like this? Thanks.

Answer 1

There is no difference between

data a;
set b;
run;

and

data a;
merge b;
run;

other than the likely warning/error you will receive from the merge statement not having a by statement. If you include the by statement in both, there becomes no difference at all.

Merge is in fact a special case of Set, as KP6's answer explains. With only a single dataset, it is identical.