statement reads observations from one or more SAS data sets and uses
them to build a new data set.
The SET statement for
concatenating data sets has the following form:
the two or more SAS data sets to concatenate. The observations from
the first data set that you name in the SET statement appear first
in the new data set. The observations from the second data set follow
those from the first data set, and so on. The list can contain any
number of data sets.