MERGE INTO mt_tranchetext mergeTable

USING

(SELECT udtranche, udfo FROM fis.ft_tranche) drivingTable

ON (mergeTable.udtranche = drivingTable.udtranche AND 

       mergeTable.udtext='PERF_MESSUNG_START' AND 

       mergeTable.dtupdate > to_date('20170112', 'yyyymmdd)'))

WHEN MATCHED THEN 

  UPDATE SET mergeTable.udfo = drivingTable.u

MERGE INTO mt_tranchetext mergeTable

USING

(WITH drivingTable AS (SELECT udtranche, udfo FROM fis.ft_tranche) 

SELECT drivingTable.udfo, drivingTable.udtranche FROM drivingTable 

WHERE drivingTable.udfo NOT IN (SELECT udfo FROM mt_tranchetext  WHERE mt_tranchetext.udtext='PERF_MESSUNG_START') ) drivingTable

ON (mergeTable.udtranche = drivingTable.udtranche 

    AND mergeTable.udtext='PERF_MESSUNG_START'  

    AND mergeTable.dtupdate > to_date('20170112', 'yyyymmdd)') 

   )

WHEN MATCHED THEN 

 UPDATE SET mergeTable.udfo = drivingTable.udfo