SQL & PL/SQL

Hi,

could someone give me a run down of the implications of MERGE by ROWID in such a fashion:


MERGE
INTO XXWT_AP_ACCRUALS_RECEIPT_F EXT
USING (
SELECT PO_DISTRIBUTION_ID,
ROWID AS ARR_ROWID,
FUNC_ACCRUAL_AMOUNT * ((QUANTITY_RECEIVED_ATOMIC - QUANTITY_BILLED_ATOMIC)
/ SUM( QUANTITY_RECEIVED_ATOMIC-QUANTITY_BILLED_ATOMIC) OVER (PARTITION BY PO_DISTRIBUTION_ID) ) AS ACCRUAL_AMOUNT_ATOMIC
FROM XXWT_AP_ACCRUALS_RECEIPT_F AAR
WHERE PO_DISTRIBUTION_ID IS NOT NULL
AND PERIOD_KEY = LN_PERIOD_KEY
AND SEGMENT1_LEGAL_ENTITY = LV_COMPANY
AND NVL(QUANTITY_ACCRUED,0) !=0
) SUB
ON (
EXT.ROWID = SUB.ARR_ROWID
)
WHEN MATCHED THEN
UPDATE SET EXT.ACCRUAL_AMOUNT_ATOMIC = SUB.ACCRUAL_AMOUNT_ATOMIC




Can this lead to an "Unstable Set of Rows?". Is it possible for the ROWID's to change during the execution of this statement - meaning certain ROWIDs identified in the SELECT will not actually be updated when it comes to the MERGE operation?

Basically, is it sound practice to use ROWID to merge on - in cases where you dont have a WHEN NOT MATCHED condition?

Thanks in advance for any input......