append statement is used to append one SET to the end of another.
If the source DSET has any column names not present in the destination DSET then additional columns are automatically created in the destination DSET. These additional columns will contain blank values by default.
If one or more column names are present in both DSETs then the columns copied from the source DSET may be re-ordered into the same order as that used by the destination DSET.
At the end of the operation, the destination DSET will contain all the data from both DSETs, and the source DSET is unchanged.
Given the following DSETs:
DSET ID: example.data
DSET ID: example2.data
append example2.data to example.data will result in the following destination DSET (example.data):