Chapter 11: BY-Group Processing in SAS Programs

Definition of BY-Group Processing

BY-group processing is a method of processing observations from one or more SAS data sets that are grouped or ordered by values of one or more common variables . You can use BY-group processing in both DATA and PROC steps.

The most common use of BY-group processing in the DATA step is to combine two or more SAS data sets by using the BY statement with a SET, MERGE, MODIFY, or UPDATE statement. When you create reports or summaries with SAS procedures, BY-group processing allows you to group information in the output according to values of one or more variables.