> On Oct 6, 2023, at 7:47 AM, Tom Lane <tgl@xxxxxxxxxxxxx> wrote: > > Luca Ferrari <fluca1978@xxxxxxxxx> writes: >> I'm wondering why in COPY TO (file or program) I cannot use generated >> columns: since I'm pushing data out of the table, why they are not >> allowed? > > There's a comment about that in copy.c: > > * We don't include generated columns in the generated full list and we don't > * allow them to be specified explicitly. They don't make sense for COPY > * FROM, but we could possibly allow them for COPY TO. But this way it's at > * least ensured that whatever we copy out can be copied back in. > > Not sure how convincing that reasoning is, but it was at least > thought about. I do agree with it as far as the default column > list goes, but maybe we could allow explicit selection of these > columns in COPY TO. > > regards, tom lane > > What would be copied? The forumla? Seems to me one is using “the fast option” so adding the column which can be regenerated is overhead.
