Thanks, thats exactly what I thought first, especcially because I read somewhere else, that this would be an error in sas 9.1 or so. But most probably it was the same misunderstanding , should read MAX sets the number of the first observation to process to the maximum <POSSIBLE> number of observations in the data set.   Thank you all for your thoughts! ... View more

Thanks, fine. There are several work-arounds, e.g. data test; set test; x=1; run; data test(drop=x); set test; by x; if last.x; run;   I just loved the idea to make it simple and did not see my misunderstanding... Best Uli ... View more

THANKS,   got my mistake.   MAX is NOT the number of observations in the current data set, BUT the maximal possible number of observations in any data set!   So I will work around that, its a pity, would have been so nice and short.   ... View more

MAX is a valid value for FIRSTOBS according SAS documentation, see http://support.sas.com/documentation/cdl/en/ledsoptsref/69751/HTML/default/viewer.htm#p0wjxoxrco6dsgn1ls5n3mbybcng.htm. Of course there are a lot of work arounds, but I intend to write a macro for several users, so the code should be as simple and understandable as possible. ... View more

The full log is   42911   data test; input var1; 42912   datalines; NOTE: The data set WORK.TEST has 4 observations and 1 variables. NOTE: DATA statement used (Total process time):       real time           0.00 seconds       cpu time            0.00 seconds 42917   ; 42918   RUN; 42919   data test; set test(firstobs=max); run; WARNING: FIRSTOBS option > number of observations in WORK.TEST. NOTE: There were 0 observations read from the data set WORK.TEST. NOTE: The data set WORK.TEST has 0 observations and 1 variables. NOTE: DATA statement used (Total process time):       real time           0.00 seconds       cpu time            0.00 seconds ... View more