SELECT temp.*, (COST - acc_dcost) final_cost
FROM (SELECT asset.code, deprec.yr, COST, deprec.dcost dcost_year,
SUM (dcost) OVER (PARTITION BY deprec.code ORDER BY yr)
acc_dcost
FROM (SELECT 1003 code, 10000 COST
FROM DUAL) asset,
(SELECT 2001 yr, 1003 code, 163 dcost
FROM DUAL
UNION ALL
SELECT 2002, 1003, 161
FROM DUAL
UNION ALL
SELECT 2003, 1003, 158
FROM DUAL) deprec) temp
