On Wed, Dec 7, 2022 at 10:34 AM Andres Freund <and...@anarazel.de> wrote:
> > +{ oid => '8053',
> > + descr => 'get error message if string is not valid input for data
> type',
> > + proname => 'pg_input_invalid_message', provolatile => 's',
> > + prorettype => 'text', proargtypes => 'text regtype int4',
> > + prosrc => 'pg_input_invalid_message_mod' },
> > +
>
> Is there a guarantee that input functions are stable or immutable? We don't
> have any volatile input functions in core PG:
>
> SELECT provolatile, count(*) FROM pg_proc WHERE oid IN (SELECT typinput
> FROM pg_type) GROUP BY provolatile;
>
>
Effectively yes, though I'm not sure if it is formally documented or
otherwise enforced by the system.
The fact we allow stable is a bit of a sore spot, volatile would be a
terrible property for an I/O function.
David J.
