The ALTER option is used to set a password that allows altering the dataset. Refer to our article on How to Password Protect SAS Datasets?. for more details.

The KEEP statement does not affect the PDV. It only applies to the new data set.

The FIRSTOBS option specifies the number of the first observation to be read.

The DATASTMTCHK system option prevents datasets from being created with names like SET and MERGE.

The REPLACE=NO option prevents the replacement of a permanent data set.This data set option overrides the system option of the same name. REPLACE=YES is the default.

The KEEP data set option keeps only the specified variables in the new data set.

The code is incorrect because it attempts to both keep and rename the variable name in the new dataset new_dataset. Specifically, the keep=age name option in the DATA statement specifies that only the age and name variables should be kept in new_dataset. However, the rename=(fullname=name) option in the SET statement tries to rename the fullname variable from old_dataset to name.

The conflict arises because the name variable is not initially present in old_dataset (it's supposed to be renamed from fullname). Therefore, the keep=age name option in the DATA statement will not find a name variable to keep, leading to confusion.

To correct this, you could either:

1. Use keep=age fullname in the DATA statement and keep the rename=(fullname=name) in the SET statement, or
2. Rename fullname to name in old_dataset before using it in the DATA step.

data new_dataset(keep=age fullname);
set old_dataset(drop=salary rename=(fullname=name));
run;