GETOBS= Data Set Option

By default, the SAS Data in HDFS engine does not compute the number of observations in a SASHDAT file. This improves performance for SASHDAT files that are distributed among a large number of blocks, or for HDFS directories that have a large number of SASHDAT files. When you specify GETOBS=YES, the engine calculates the number of observations in a SASHDAT file.

ods select attributes;

proc datasets library=hdfs;
    contents data=sales2012(getobs=yes);
run;