From: Tom Lane <tgl@sss.pgh.pa.us>
To: =?UTF-8?Q?Vedran_Bilopavlovi=C4=87?= <vbilopav@gmail.com>
cc: pgsql-bugs@lists.postgresql.org
Subject: Re: BUG: value in information_schema.parameters.parameter_default is
 always NULL for roles t
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=?UTF-8?Q?Vedran_Bilopavlovi=C4=87?= <vbilopav@gmail.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