11gR2 : Query to optimize

Hi ,

Do you have an idea how to optimize this query  ?

Best regards.

GD.

INSERT INTO PRIM_CONTRACT
  (NO_CONTRACT,
   CD_SOURCE_FLOW,
   CD_FRT_OFFICE_SYS,
   ID_CONTRACT,
   TP_VALRISK_CONTRACT,
   TP_CAT_CONTRACT,
   DT_TRADE,
   DT_MATURITY,
   DT_VALUE,
   ID_MNA,
   ID_COLLATERAL_AGREE,
   ID_STRATEGY,
   TP_HYPER_CONTRACT,
   IND_REPORT_PERIMETER,
   NB_RESID_MATURITY,
   CD_SGN_GDR_CTPY,
   CD_GDR_CTPY,
   NO_PARTITION)
  SELECT MAX(CTR.ID_SOFTWARE || CTR.NO_DEAL) KEEP(DENSE_RANK FIRST ORDER BY ROWNUM) NO_CONTRACT,
         MAX('eqd') KEEP(DENSE_RANK FIRST ORDER BY ROWNUM) CD_SOURCE_FLOW,
         MAX(CTR.ID_SOFTWARE) KEEP(DENSE_RANK FIRST ORDER BY ROWNUM) CD_FRT_OFFICE_SYS,