Bulk load on table with trigger taking long time

I have a bulk load that is updating a table.  there is a trigger on the table which fires and updates a "history" table in another schema.  

My question is:   When this trigger fires does the entire row get updated or only the where condition fields in the row?

CREATE OR REPLACE TRIGGER "U_CASHEXPECTEDENTRY"
    AFTER UPDATE OF ACTGMETHOD_ID,CASHAMNT,CASHEXPECTEDENTRY_ID,CASHONQUANTITY_DTM,CASHOUTSTANDING,CASHRECONCASHTYPE_ID,CASHRECONREASON_ID,CREATED_BY,CREATED_DTM,END_REALEVENT_DTM,EXPECTEDPAYMENT_DTM,EXPECTED_REALEVENT_DTM,LEDGERENTRY_ID,LEDGERLINE_ID,LOT_ID,MODIFIED_BY,MODIFIED_DTM,PERCENTAGELEDGERLINE,REALEVENTHIST_ID,REALEVENT_DTM,RECONCILED_REALEVENT_ID,SECURITY_ID,SETTLEMENT_DTM ON "NIS1".CASHEXPECTEDENTRY
    REFERENCING OLD AS OLD NEW AS NRW
FOR EACH ROW
BEGIN
 IF :NRW.REALEVENT_DTM IS NOT NULL
 THEN
     UPDATE  "NIS1H".CASHEXPECTEDENTRY
     SET
     END_REALEVENT_DTM = :NRW.REALEVENT_DTM
     WHERE
     CASHEXPECTEDENTRY_ID=:OLD.CASHEXPECTEDENTRY_ID
     AND
     REALEVENT_DTM = :OLD.REALEVENT_DTM AND
     END_REALEVENT_DTM is NULL;
     INSERT INTO  "NIS1H".CASHEXPECTEDENTRY
     (
        ACTGMETHOD_ID,CASHAMNT,CASHEXPECTEDENTRY_ID,CASHONQUANTITY_DTM,CASHOUTSTANDING,CASHRECONCASHTYPE_ID,CASHRECONREASON_ID,CREATED_BY,CREATED_DTM,END_REALEVENT_DTM,EXPECTEDPAYMENT_DTM,EXPECTED_REALEVENT_DTM,LEDGERENTRY_ID,LEDGERLINE_ID,LOT_ID,MODIFIED_BY,MODIFIED_DTM,PERCENTAGELEDGERLINE,REALEVENTHIST_ID,REALEVENT_DTM,RECONCILED_REALEVENT_ID,SECURITY_ID,SETTLEMENT_DTM
     )
     VALUES
     (
         :NRW.ACTGMETHOD_ID,:NRW.CASHAMNT,:NRW.CASHEXPECTEDENTRY_ID,:NRW.CASHONQUANTITY_DTM,:NRW.CASHOUTSTANDING,:NRW.CASHRECONCASHTYPE_ID,:NRW.CASHRECONREASON_ID,:NRW.CREATED_BY,:NRW.CREATED_DTM,:NRW.END_REALEVENT_DTM,:NRW.EXPECTEDPAYMENT_DTM,:NRW.EXPECTED_REALEVENT_DTM,:NRW.LEDGERENTRY_ID,:NRW.LEDGERLINE_ID,:NRW.LOT_ID,:NRW.MODIFIED_BY,:NRW.MODIFIED_DTM,:NRW.PERCENTAGELEDGERLINE,:NRW.REALEVENTHIST_ID,:NRW.REALEVENT_DTM,:NRW.RECONCILED_REALEVENT_ID,:NRW.SECURITY_ID,:NRW.SETTLEMENT_DTM
     );
 END IF;
END;
/
SHOW ERRORS;