PostgreSQL获取函数名

SELECT
  pg_proc.proname AS "函数名称",
  pg_type.typname AS "返回值数据类型",
  pg_proc.pronargs AS "参数个数"
FROM
  pg_proc
    JOIN pg_type
   ON (pg_proc.prorettype = pg_type.oid)
WHERE
 pronamespace = (SELECT pg_namespace.oid FROM pg_namespace WHERE nspname = '模式名')