topic Re: SORTEDBY=_NULL_ in SAS Programming

SORTEDBY=_NULL_

DmytroYermak — Thu, 11 Oct 2018 09:01:15 GMT

Hi all,

Could you please say what is the context in the "SORTEDBY=_NULL_" (unfortunately I can not ask the author) in the following code:

DATA test (SORTEDBY=_NULL_);
  SET pretest;
RUN;

The dataset pretest was previously sorted by one variable.

Thank you!

Re: SORTEDBY=_NULL_

PeterClemmensen — Thu, 11 Oct 2018 09:16:31 GMT

As the SORTEDBY= Data Set Option Documentation says it "removes any existing sort indicator." 🙂

A small example demonstrates the option

data SomeData;
input x @@;
datalines;
3 2 5 1 6 4 8 5
;

proc sort data=SomeData;
   by x;
run;

/* SAS knows that SomeData is sorted (Sorted=Yes) */
proc contents data=SomeData;
run;

/* Sortedby=_null_ forces SAS to forget the sort information (Sorted=No) */
data test(sortedby=_null_);
   set SomeData;
run;
proc contents data=test;
run;

Re: SORTEDBY=_NULL_

Amir — Thu, 11 Oct 2018 09:07:30 GMT

Hi,

Taken from the documentation:

http://support.sas.com/documentation/cdl/en/lrdict/64316/HTML/default/viewer.htm#a000131184.htm

removes any existing sort indicator

Regards,

Amir.

Re: SORTEDBY=_NULL_

DmytroYermak — Thu, 11 Oct 2018 10:00:00 GMT

Thank you, draycut. I just do not understand for what was it needed that "SAS to forget the sort information"...

Re: SORTEDBY=_NULL_

Tom — Thu, 11 Oct 2018 12:21:25 GMT

In that step it is not needed since SAS will not be storing any SORTEDBY information for a dataset created in that way.

Perhaps they had a previous process that did generate the data in a sorted order and they wanted to force SAS to store the fact it was sorted. So they were in the habit of using the SORTEDBY= dataset option and instead of removing it totally they just set the list of variables to _NULL_.