How to remove duplicated records\observations WITHOUT sorting in SAS？

Question

I wonder if there is a way to unduplicate records WITHOUT sorting?Sometimes, I want to keep original order and just want to remove duplicated records.

I

Answer 1

/* Give each record in the original dataset and row number */
data with_id ;
  set mydata ;
  _id = _n_ ;
run ;

/* Remove dupes */
proc sort data=with_id nodupkey ;
  by var1 var2 var3 ;
run ;

/* Sort back into original order */
proc sort data=with_id ;
  by _id ;
run ;