Docs for Generated Columns
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docker run --rm -p 5432:5432 ghcr.io/hackorum-dev/postgres-patch:t76484psql -h localhost -U postgresBuilt from patchset v3 (message #3), July 28, 2026 at 01:39 PM.
Every patchset is also pushed to a branch of our PostgreSQL fork, so you can check out the same tree CI built. Without a PostgreSQL checkout:
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git remote add hackorum https://github.com/hackorum-dev/postgres.gitthen, for this patchset and every later one:
git fetch hackorum t76484_3 && git checkout t76484_3Patchset v3 (message #3) is on t76484_3
Hi,
while reading though the docs of the upcoming pg12 features, I stumbled upon some wording regarding generated columns:
both in create_table.sgml [1]https://www.postgresql.org/docs/devel/sql-createtable.html and create_foreign_table.sgml [2]https://www.postgresql.org/docs/devel/sql-createforeigntable.html the paragraph for the GENERATED ALWAYS AS clause is introduced with
This clause creates the column as a generated column. The column cannot be written to, and when read it will be computed from the specified expression.
To me this sounds confusing, if not wrong. Till v8 of the patch were STORED and VIRTUAL generated columns were described afterwards this was less obvious but now with only STORED it sounds like a reference to the VIRTUAL variant. Not being I native english speaker I'm restrained to send a patch but may I suggest the following for discussion:
The column cannot be written to, and when read the result of the specified expression will be returned.
Best regards
Tobias Bussmann
[1]: https://www.postgresql.org/docs/devel/sql-createtable.html
[2]: https://www.postgresql.org/docs/devel/sql-createforeigntable.html
On 5/23/19 5:50 PM, Tobias Bussmann wrote:
while reading though the docs of the upcoming pg12 features, I
stumbled upon some wording regarding generated columns: both in
create_table.sgml [1] and create_foreign_table.sgml [2] the paragraph
for the GENERATED ALWAYS AS clause is introduced withThis clause creates the column as a generated column. The column
cannot be written to, and when read it will be computed from the
specified expression.
To me this sounds confusing, if not wrong. Till v8 of the patch were
STORED and VIRTUAL generated columns were described afterwards this
was less obvious but now with only STORED it sounds like a reference
to the VIRTUAL variant.
No doubt this is flat out wrong.
Not being I native english speaker I'm restrained to send a patch but
may I suggest the following for discussion:
The column cannot be written to, and when read the result of the
specified expression will be returned.
That sounds reasonable to me.
Joe
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Crunchy Data - http://crunchydata.com
PostgreSQL Support for Secure Enterprises
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On 24.05.2019 14:21, Joe Conway <mail@joeconway.com> wrote:
The column cannot be written to, and when read the result of the
specified expression will be returned.That sounds reasonable to me.
Thank you for confirmation and review. Please find attached my proposed little doc patch for this issue.
Tobias
On 2019-05-26 16:42, Tobias Bussmann wrote:
On 24.05.2019 14:21, Joe Conway <mail@joeconway.com> wrote:
The column cannot be written to, and when read the result of the
specified expression will be returned.That sounds reasonable to me.
Thank you for confirmation and review. Please find attached my proposed little doc patch for this issue.
committed
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services