Program Data Vector (PDV)
The PDV is a logical area in memory where SAS builds a data set, one observation at a time. When a program executes, SAS reads data values or creates them by executing SAS language statements. The data values are assigned to the appropriate variables in the PDV. From here, SAS writes the values to a SAS data set as a single observation.
Along with data set variables and computed variables, the PDV contains these automatic variables:
the _N_ variable, which counts the number of times the DATA step iterates.
the _ERROR_ variable, which signals the occurrence of an error caused by the data during execution. The value of _ERROR_ is 0 when there are no errors. When an error occurs, whether ...