Document COPY FROM WHERE restrictions on generated and system columns
Hi,
I found that generated columns and system columns cannot be used in
COPY FROM WHERE expressions, but the COPY docs still mentions
only the restriction on subqueries.
So I've created the attached patch which updates the docs to also list
generated columns and system columns as unsupported in COPY FROM WHERE
expressions.
Since generated columns have been rejected in COPY FROM WHERE since
v13, that docs change should be backpatched to all supported branches.
But the system-column restriction was introduced in v19, so that part
does not need to be backpatched.
Thoughts?
Regards,
--
Fujii Masao
Attachments:
v1-v14-18-0001-doc-Clarify-COPY-FROM-WHERE-expression-restrictio.txttext/plain; charset=US-ASCII; name=v1-v14-18-0001-doc-Clarify-COPY-FROM-WHERE-expression-restrictio.txtDownload+5-5
v1-0001-doc-Clarify-COPY-FROM-WHERE-expression-restrictio.patchapplication/octet-stream; name=v1-0001-doc-Clarify-COPY-FROM-WHERE-expression-restrictio.patchDownload+5-5
Hi,
On Thu, 2 Jul 2026 at 18:41, Fujii Masao <masao.fujii@gmail.com> wrote:
Hi,
I found that generated columns and system columns cannot be used in
COPY FROM WHERE expressions, but the COPY docs still mentions
only the restriction on subqueries.So I've created the attached patch which updates the docs to also list
generated columns and system columns as unsupported in COPY FROM WHERE
expressions.Since generated columns have been rejected in COPY FROM WHERE since
v13, that docs change should be backpatched to all supported branches.
But the system-column restriction was introduced in v19, so that part
does not need to be backpatched.Thoughts?
Thanks for the patch!
I think it makes sense to add the system columns and generated
columns limitation to the documentation, patch LGTM.
Regards,
Ayush
On Thu, Jul 2, 2026 at 10:16 PM Ayush Tiwari
<ayushtiwari.slg01@gmail.com> wrote:
Thanks for the patch!
I think it makes sense to add the system columns and generated
columns limitation to the documentation, patch LGTM.
Thanks for the review! I've pushed the patch.
Regards,
--
Fujii Masao