WITH TBL1 AS
(
    SELECT '01' UPID, 'A' DOWNID, '001' ETR FROM DUAL UNION ALL
    SELECT '01'     , 'A'       , '002'     FROM DUAL UNION ALL
    SELECT '01'     , 'A'       , '003'     FROM DUAL UNION ALL
    SELECT '01'     , 'A'       , '004'     FROM DUAL UNION ALL
    SELECT '01'     , 'B'       , '001'     FROM DUAL UNION ALL     
    SELECT '01'     , 'B'       , '002'     FROM DUAL UNION ALL
    SELECT '02'     , 'A'       , '001'     FROM DUAL UNION ALL
    SELECT '02'     , 'A'       , '002'     FROM DUAL UNION ALL
    SELECT '02'     , 'A'       , '003'     FROM DUAL                
)
SELECT  UPID
       ,DOWNID
       ,ROW_NUMBER() OVER (PARTITION BY UPID, DOWNID ORDER BY UPID, DOWNID) SEQ
       ,ETR
  FROM  TBL1
 GROUP  BY UPID, DOWNID, ETR;

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