SELECT A.MAT_NO

, A.MAT_ID

, A.DSN_PRNT_MAT_NO

, A.PROJ_NO

, LEVEL

FROM PHA_MBOM A

WHERE A.PROJ_NO = 'TKSFUK'

AND A.IF_STAT = 'D'

AND A.DEL_ORDR <> 'X'

AND LEVEL <> 1

START WITH A.MAT_ID IN (

SELECT DISTINCT T1.MAT_ID

FROM PHA_MBOM T1

, PHA_MBOM_MA T2

WHERE T1.PROJ_NO = 'TKSFUK'

AND T1.DSN_CD IN ('UU', 'MP')

AND T1.BOM_KND IN ('AS', 'IF')

AND T1.M_ID = T2.BOM_ID

AND T1.G_REV = T2.CHG_REV

AND T2.CAD_OBJ_TP IN ('CS','CH')

) /* 2만건 */

AND A.PROJ_NO = 'TKSFUK'

CONNECT BY PRIOR A.MAT_ID = A.DSN_PRNT_MAT_NO

AND PRIOR A.PROJ_NO = A.PROJ_NO

위에서 start with 절을 빼면 속도가 그나마 좀 나오는데

start with 절을 넣으면 속도가 기존속도보다 20배 늦어지네요.

제가 무엇을 잘못했나요?