Re: Error-safe user functions

Hi,

On 2022-12-06 15:21:09 -0500, Tom Lane wrote:
> +{ oid => '8050', descr => 'test whether string is valid input for data type',
> + proname => 'pg_input_is_valid', provolatile => 's', prorettype => 'bool',
> + proargtypes => 'text regtype', prosrc => 'pg_input_is_valid' },
> +{ oid => '8051', descr => 'test whether string is valid input for data type',
> + proname => 'pg_input_is_valid', provolatile => 's', prorettype => 'bool',
> + proargtypes => 'text regtype int4', prosrc => 'pg_input_is_valid_mod' },
> +{ oid => '8052',
> + 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',
> + prosrc => 'pg_input_invalid_message' },
> +{ 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;

Greetings,

Andres Freund