Delete rows not in Base Input SAS Data Set Select this option when you only want rows in the Output Data Set that exist in the Base Input SAS Data Set. Note: This option is available only if the Delete nonmatching rows option is not checked. To Specify That Rows Not in the Base Input Data Set Be Deleted: Ensure that the Delete nonmatching rows box is not checked. Check the Delete Rows Not in Base Input SAS Data Set box.