MERGE /*+ USE_HASH(B A) */
  INTO TB_CTNS_030 B
USING (
    SELECT
      A.LECT_SEQ  AS BB
      ,A.CBT_LECT_ID

\tFROM\t
\t\tTB_CTNS_020 A    
) A
ON(
   A.CBT_LECT_ID = B.CBT_LECT_ID
)
WHEN MATCHED THEN
UPDATE SET
  B.LECT_SEQ = A.LECT_SEQ