When you exchange more
than one pair of names in one EXCHANGE statement, PROC DATASETS performs
the exchanges in the order in which the names of the SAS files occur
in the directory listing, not in the order in which you list the exchanges
in the EXCHANGE statement.
If the
name SAS
file does not exist in the SAS library, PROC DATASETS stops processing
the RUN group that contains the EXCHANGE statement and issues an error
message. To override this behavior, specify the NOWARN option in
the PROC DATASETS statement.
The EXCHANGE statement
also exchanges the associated indexes so that they correspond with
the new name.
The EXCHANGE statement
only allows two existing generation groups to exchange names. You
cannot exchange a specific generation number with either an existing
base version or another generation number.