Oracle: DBA_METHOD_PARAMS

select
   met.owner,
   met.method_name,
   met.method_type,
   met.final,
   met.instantiable,
   met.overriding,
   met.inherited,
   listagg( par.param_name || ' ' || lower(par.param_mode || ' ' || par.param_type_name), ', ') within group (order by par.param_no) params,
   res.result_type_name,
   met.method_no
from
   dba_type_methods  met                                                      join
   dba_method_params par  on met.owner        = par.owner       and
                             met.type_name    = par.type_name   and
                             met.method_name  = par.method_name and
                             met.method_no    = par.method_no            left join
   dba_method_results res on met.owner        = res.owner       and
                             met.type_name    = res.type_name   and
                             met.method_name  = res.method_name and
                             met.method_no    = res.method_no
where
   met.inherited = 'NO'                  and
   --
   met.owner     = 'SYS'                 and
   met.type_name = 'JSON_ELEMENT_T'
-- met.type_name = 'JSON_OBJECT_T'
-- met.type_name = 'JSON_ARRAY_T'
-- met.type_name = 'JSON_SCALAR_T'
group by
   met.owner,
   met.method_name,
   met.method_type,
   met.final,
   met.instantiable,
   met.overriding,
   met.inherited,
   res.result_type_name,
   met.method_no
order by
   met.method_name,
   met.method_no
;