Even better, how about having -append- return the number of common
variables, and the number of unique variables from the master and using
datasets? Then one could automate the checking of whether it worked...
I agree, these would be useful outputs. But unlike merge, which can do many
things and thus often needs to be checked (via tab _merge, etc.), append in
the mode that it is usually used is a one-trick pony: it just concats the
datafiles. Now I see that it is capable of doing fancier things, and
sometimes that might be what someone is trying to do. But I guess something
that would give a warning when the number of variables in the two datasets
differ, and a severe warning when they lack any commonality, would be
helpful. In my experience, most of the time when using append one doesn't
think that either of those conditions should occur.
