Re: why generated columsn cannot be used in COPY TO?

On Fri, Oct 6, 2023 at 4:59 PM Rob Sargent <robjsargent(at)gmail(dot)com> wrote:

> What would be copied? The formula?

Of course not. That's DDL, not DML IMHO.

> Seems to me one is using “the fast option” so adding the column which can
> be regenerated is overhead.
>

Regenerated by whom? COPY TO to is output to the outside world.
Nothing says it will come back to PostgreSQL later. COPY is not only for
backups.
I use COPY to "stream" rows out for processing, combines the best of SELECT
and the incremental nature of CURSOR, for the best latency and throughput.

All that said, that's a work-around like Andreas showed.
I agree with Tom that ignoring them in the default list makes sense,
but that if explicitly asked for, they should be copied out. My $0.02.