Oracle Query : Tree의 ChildNode 전체를 가져오는법

SELECT  pgm_no
   ,pgm_id
   ,pgm_name
   ,pgm_kind_code
   ,picture
   ,select_picture
   ,sort_order
   ,parent_pgm
 FROM  pf_pgm_mst
 where  pgm_kind_code='P'
  CONNECT BY PRIOR    PGM_NO  = PARENT_PGM
  start with       PGM_NO = '00015'