Certain data set options cause warning or errors and are not honored.

Below are some of the warnings or errors you may get.

   WARNING:  The variable  in the DROP, KEEP, or
   RENAME list has never been referenced.
  

• The WHERE data set option is honored.
• The KEEP and DROP data set options cause warnings.

Operating System and Release Information

data _null_;
   length k 8;
   length d $10;
   declare hash h(ordered: 'y');
   h.defineKey('k');
   h.defineData('k', 'd');
   h.defineDone();
   k = 99;
   d = 'abc';
   h.add();
   k = 199;
   d = 'def';
   h.add();
   h.output(dataset: 'work.x (where=(k=99))');
   h.output(dataset: 'work.y (drop=k) ');
 run;

SAS LOG:
1    data _null_;
2       length k 8;
3       length d $10;
4       declare hash h(ordered: 'y');
5       h.defineKey('k');
6       h.defineData('k', 'd');
7       h.defineDone();
8       k = 99;
9       d = 'abc';
10      h.add();
11      k = 199;
12      d = 'def';
13      h.add();
14      h.output(dataset: 'work.x (where=(k=99))');
15      h.output(dataset: 'work.y (drop=k) ');
16   run;

NOTE: The data set WORK.X has 1 observations and 2 variables.
WARNING: The variable k in the DROP, KEEP, or RENAME list has never been referenced.
NOTE: The data set WORK.Y has 2 observations and 2 variables.
NOTE: DATA statement used (Total process time):
      real time           0.06 seconds
      cpu time            0.04 seconds
      

      


                          work.x (where=(k=99))                         1

                            Obs     k     d

                             1     99    abc


                             work.y (drop=k)                            2

                           Obs     k      d

                            1      99    abc
                            2     199    def