Using MERGE across schemas with Analytic functions

 I have the following MERGE statement that is taking hours to run:

MERGE

 INTO BIFND.AR_TRX_DETAIL T

USING ( SELECT SRCCOMPANYIDX,

               SRCGLOBALIDX,

               ARTRXDTLSEQ,

               ARTRXHDRIDX

          FROM BISTGV.AR_TRX_DETAIL

      GROUP BY SRCCOMPANYIDX,

               SRCGLOBALIDX,

               ARTRXDTLSEQ,

               ARTRXHDRIDX ) S

   ON ( T.SRCCOMPANYIDX = S.SRCCOMPANYIDX AND

        T.SRCGLOBALIDX  = S.SRCGLOBALIDX AND

        T.ARTRXDTLSEQ   = S.ARTRXDTLSEQ AND

        T.ARTRXHDRIDX   = S.ARTRXHDRIDX )

WHEN MATCHED THEN

   UPDATE

      SET T.CURRENTIND = 'N'

Details

BIFND.AR_TRX_DETAIL currently has 36,945,985 rows. It is stored in the BIFND tablespace

BISTGV.AR_TRX_DETAIL is a view with SQL analytics. It is stored in the BISTG tablespace, and is defined as follows: