Re: BUG: value in information_schema.parameters.parameter_default is always NULL for roles t

=?UTF-8?Q?Vedran_Bilopavlovi=C4=87?= <vbilopav(at)gmail(dot)com> writes:
> Values in table *information_schema.parameters*, column *parameter_default*,
> are always NULL only for roles that are not superuser.

I see no bug there. The manual defines parameter_default as

The default expression of the parameter, or null if none or if the
function is not owned by a currently enabled role.

A superuser is considered to own everything, but for mere-mortal
roles a result would only appear for functions you own. The
SQL implementation of the view appears to match this definition:

CASE WHEN pg_has_role(proowner, 'USAGE')
THEN pg_get_function_arg_default(p_oid, (ss.x).n)
ELSE NULL END

You could certainly quibble with the value of hiding the information
when it's readily available from our system catalogs --- but this
is a SQL-standard-defined view so we implement it as the standard
says, and this is what the standard says it should do.

> There is a workaround by using pg_proc table:

I'd recommend using something from the pg_get_function*() family.

regards, tom lane