clearly when you use a where clause in data set options, it doesn't use the conditions of the where statement . This causes a WARNING if A is read on the SET statement only with WHERE clauses[pre]25 data B;
26 set A(where=(i<8)) ;
27 where i>3;
WARNING: The WHERE statement cannot be applied to a data set on
the last SET/MERGE/UPDATE/MODIFY statement. Either
the data sets listed failed with open errors or they
already specify a WHERE data set option.
NOTE: There were 7 observations read from the data set WORK.A.
NOTE: The data set WORK.B has 7 [/pre] This is tested on SAS9.2
It may be different on your release.