Subject: pgsql: doc: Clarify COPY FROM WHERE expression restrictions

From: Fujii Masao <[email-masked]>
Date: Wed, 08 Jul 2026 03:46:53 +0000

doc: Clarify COPY FROM WHERE expression restrictions

Commit aa606b9316a disallowed generated columns in COPY FROM WHERE
expressions, and commit 21c69dc73f9 disallowed system columns.
However, the COPY reference page still mentions only the restriction
on subqueries.

Update the documentation to also list generated columns and system
columns as unsupported in COPY FROM WHERE expressions.

Backpatch the generated-column documentation change to all supported
versions. Backpatch the system-column documentation change to v19,
where that restriction was introduced.

Author: Fujii Masao <[email-masked]>
Reviewed-by: Ayush Tiwari <[email-masked]>
Discussion: https://postgr.es/m/CAHGQGwEgxErc54yVOAVWCsr1O=[email-masked]
Backpatch-through: 14

Branch
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REL_19_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/64ed30fda8d77782bd69297e3892895ca9f84816

Modified Files
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doc/src/sgml/ref/copy.sgml | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)