What is the difference between the MERGE and APPEND procedures in SAS?

What is the difference between the MERGE and APPEND procedures in SAS?

Both the MERGE and APPEND procedures in SAS are used to combine datasets, but they have key differences:

1. MERGE Procedure: The MERGE procedure in SAS is used to combine datasets by matching one or more variables. This procedure creates a new dataset with both the matching and non-matching observations from the input datasets. It requires the datasets to be sorted by the merging variables.
2. APPEND Procedure: The APPEND procedure, on the other hand, is used to stack datasets on top of each other. It simply appends one dataset onto the end of another, regardless of any matching variables. The datasets do not need to be sorted for the APPEND procedure.

Ultimately, the choice between using the MERGE and APPEND procedures in SAS depends on the specific requirements of the data merging task at hand.