Re: BUG #19644: byteaout, float8out and float4out are marked IMMUTABLE but depend on GUCs

On Tue, Sep 1, 2026 at 10:12 PM PG Bug reporting form
<noreply(at)postgresql(dot)org> wrote:
> Suggested fix
> =============
>
> Mark byteaout, float8out and float4out (and the corresponding casts to text)
> STABLE rather than IMMUTABLE, matching date_out, interval_out and cash_out.

+1 to making such changes on master, even though they would cause
several compatibility issues for existing users...

OTOH, for the stable branches, such catalog changes would not be
acceptable. So perhaps the practical option might be just document
the issue and how to handle it during version upgrade in the docs and
release notes, for example.

> Prior discussion
> ================
>
> I searched the mailing list archives, the TODO list and the FAQ and found no
> prior report of this. If it overlaps something I missed, I would be glad to
> be
> pointed at it.

The same issue seems to have been reported previously at [1].

Regards,

[1] https://www.postgresql.org/message-id/17398-8fb0c02a60e2e565%40postgresql.org

--
Fujii Masao