1)COMPILATION Phase:

When you submit a DATA step, it reads the input statements it creates an input buffer and brings the variables and observations. it is a logical MEMORY area and pdv brings the observations at a time from input buffer 

and checks the errors. PDV contains 2 automatic variables _n_ & _error_, these checks the errors in observations.

_n_: indicates the no of OBS.

_error_: 1 if ERROR occured

0 if no error

After that it assigns the data values to appropriate variable and builds a sas dataset.

1)Compilation Phase:

When you submit a DATA step, it reads the input statements it creates an input buffer and brings the variables and observations. it is a logical memory area and pdv brings the observations at a time from input buffer 

and checks the errors. PDV contains 2 automatic variables _n_ & _error_, these checks the errors in observations.

_n_: indicates the no of obs.

_error_: 1 if error occured

0 if no error

After that it assigns the data values to appropriate variable and builds a sas dataset.