text: SELECT castsource::regtype AS "기존자료형", 
         casttarget::regtype AS "대상자료형", 
         castfunc::regproc AS "함수", 
         CASE 
           WHEN ca.castcontext = 'a' THEN '대입' 
           WHEN ca.castcontext = 'i' THEN '묵시' 
           ELSE '명시' 
         END        AS "사용상황", 
         CASE 
           WHEN ca.castmethod = 'i' THEN '입출력' 
           WHEN ca.castmethod = 'f' THEN '함수' 
           ELSE '그냥' 
         END        AS "종류" 
  FROM   pg_cast ca
  ORDER  BY 1 