Fujii Masao <masao(dot)fujii(at)gmail(dot)com> writes:
> On Tue, Sep 1, 2026 at 10:12 PM PG Bug reporting form
> <noreply(at)postgresql(dot)org> wrote:
>> 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...
I agree with changing this on master, but I see no reason to do
anything whatever in the back branches. There are few situations
where the mutability marking of a datatype output function matters,
and even if it does, you don't see an actual problem unless you
change one of these GUCs mid-query. If it were a big deal,
we would have noticed this ages ago.
regards, tom lane