Ich glaube, Sie wollen:
SELECT B.NO_KLAIM AS id,
a.amount AS amount_a,
B.AMOUNT AS amount_b,
a.amount - SUM (B.AMOUNT)
OVER (partition by b.no_klaim ORDER BY B.cp_id ROWS UNBOUNDED PRECEDING)
AS running_balance
FROM TRX_TITIPAN A
JOIN
TRX_KLAIM_TITIPAN B
ON A.NO_RESI_TITIPAN = B.NO_RESI_TITIPAN