Hi, I was just going through something and realized a strange usage of Obs dataset option. I was under an impression that OBS=option can be used anywhere with dataset to limit the number of observation but it proved wrong Consider below example: data test; input a ; datalines; 1 2 3 4 1 3 45 26 34 ; run; proc sort data=test  out= test1(obs=3) nodupkey; by a; run; In the above code, Obs=3 doesnt limit the number of observations. Can someone please highlight the reason of it as it is really strange for me being beginner in SAS? Logs below: 37 data test; 38 input a ; 39 datalines; NOTE: The data set WORK.TEST has 9 observations and 1 variables. NOTE: DATA statement used (Total process time): real time 0.01 seconds cpu time 0.00 seconds 49 ; 50 run; 51 52 proc sort data=test out= test1 (obs=3) nodupkey; 53 by a; 54 run; NOTE: There were 9 observations read from the data set WORK.TEST. NOTE: 2 observations with duplicate key values were deleted. NOTE: The data set WORK.TEST1 has 7 observations and 1 variables. NOTE: PROCEDURE SORT used (Total process time): real time 0.03 seconds cpu time 0.03 seconds ... View more