How do you concatenate datasets in SAS?

To concatenate datasets in SAS, the SET statement in a DATA step is the most straightforward and commonly used method. When utilizing the SET statement, you can specify multiple datasets within the same DATA step. SAS will stack the datasets on top of each other, combining them into a single dataset with all the observations from the specified datasets.

For instance, if you have two datasets, 'dataset1' and 'dataset2', using the following code will create a new dataset that contains all the rows from both datasets:

data combined;
    set dataset1 dataset2;
run;

This code clearly indicates that SAS should read all the observations from both 'dataset1' and 'dataset2' in order, thus achieving concatenation.

While other methods such as PROC APPEND and PROC SQL can also be used to combine datasets, they serve slightly different purposes or may involve more complexity than using the SET statement directly in a DATA step. MERGE is specifically for merging datasets based on common variables rather than concatenating them, and PROC SQL, while powerful, is generally more suited for structured query operations rather than simple concatenation tasks.