"V. A." <a2891891@smail.Uni-Koeln.DE> writes:
> My problem is, that I don't know how I can tell the copy-command to
> leave the first field untouched, so that it gets the default value from a
> sequence....
You can't. COPY is for plain verbatim dumping and reloading of data.
Use INSERT if you need to have any calculations done.
regards, tom lane