I have noticed that if my where clause looks something like this:
not( missing( ben_per_start_date ) | missing( ben_per_end_date ) )
SAS turns it into this logical equivalence
(not MISSING(ben_per_start_date)) and (not MISSING(ben_per_end_date)
Does this mean that I am coding my original incorrectly or inefficiently?
- Jack
@Kurt_Bremser Are you writing that there are fewer comparisons using the AND operator because in the first expression is false, the second is not evaluated?
What evidence do you have that it is doing that?
That's what I posted.
The first piece of code is from the submitted SAS code.
The second piece of code was lifted from the SAS log.
Sorry if that wasn't clear.
For some obscure reason, SAS/SQL is very poor at handling OR operations. So, I guess it prefers the logical AND equivalent. Since both are logically equivalent, you should use the version that's clearer to you.
When you have an and instead of an or, you can shortcut the condition when the first part is false. This reduces the overall amount of comparisons that must be made.
@Kurt_Bremser Are you writing that there are fewer comparisons using the AND operator because in the first expression is false, the second is not evaluated?
You could say the same thing of an OR operation. If the first operand is true, the second one doesn't need to be evaluated.
Are you ready for the spotlight? We're accepting content ideas for SAS Innovate 2025 to be held May 6-9 in Orlando, FL. The call is open until September 25. Read more here about why you should contribute and what is in it for you!
Learn how use the CAT functions in SAS to join values from multiple variables into a single value.
Find more tutorials on the SAS Users YouTube channel.