Horton

Re: support ALTER COLUMN SET EXPRESSION over virtual generated column with check constraint

jian he <jian.universality@gmail.com>

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From: jian he <jian.universality@gmail.com>
To: Matheus Alcantara <matheusssilv97@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2026-01-21T05:10:20Z
Lists: pgsql-hackers

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On Wed, Jan 21, 2026 at 2:48 AM Matheus Alcantara
<matheusssilv97@gmail.com> wrote:
>

> Thanks for the new version. Just a minor comment
>
> +      Replacing the expression of a virtual generated columns do not require a
> +      table rewrite, however if the column is part of a <literal>CHECK</literal>
> +      constraint expression, the constraint will be rebuilt, requiring a table
> +      scan to ensure that existing rows meet the constraint.
>
> I think that it sounds better with: "Replacing the expression of a
> virtual generated column does not require a table rewrite..."
>
> --
> Matheus Alcantara
> EDB: https://www.enterprisedb.com
>

sure. please check the attached.


--
jian
https://www.enterprisedb.com

Commits

  1. Allow ALTER COLUMN SET EXPRESSION on virtual columns with CHECK constraints