## Recursive RunningTotal calculate

 Author Message Catcha Valued Member Group: General Forum Members Points: 70 Visits: 169 Hi All,I need to calculate running total (totalInterestedPaid) for the following temp table (#tmpInterestedPaid)tran_date Calc_interest_accrued Interest_paid TotalInterestPaid20120908 54.06 NULL 020120910 54.06 NULL 020120911 24.04 112.35 020120913 23.67 20.12 020120914 23.67 NULL 0The totalInterestedPaid should be additional the previous date Calc_interest_accrued with today Calc_interest_accrued but whenever there is interest_paid is not equal to null the Running total will be reset to zero. The expected result is as follow tran_date Calc_interest_accrued Interest_paid TotalInterestPaid20120908 54.06 NULL 54.0620120910 54.06 NULL 108.1220120911 24.04 112.35 132.1620120913 23.67 20.12 23.6720120914 23.67 NULL 47.34I believe recursive CTE will work but just not sure how to code it.Thanks,Derek dwain.c SSCertifiable Group: General Forum Members Points: 7213 Visits: 6431 I'm thinking that you may have your interest accured and interest paid terminology a little mixed up here.Take a look at the following Quirky Update (QU) method for calculating what I think you need.`CREATE TABLE #Pmts (tran_date DATETIME PRIMARY KEY CLUSTERED ,Calc_interest_accrued MONEY, Interest_paid MONEY ,TotalInterestPaid MONEY, TotalInterestAccrued MONEY ,TotalInterestDue AS (TotalInterestAccrued - TotalInterestPaid))INSERT INTO #Pmts (tran_date, Calc_interest_accrued, Interest_paid ,TotalInterestPaid, TotalInterestAccrued)SELECT '2012-09-08',54.06,NULL,0,0UNION ALL SELECT '2012-09-10',54.06,NULL,0,0UNION ALL SELECT '2012-09-11',24.04,112.35,0,0UNION ALL SELECT '2012-09-13',23.67,20.12,0,0UNION ALL SELECT '2012-09-14',23.67,NULL,0,0DECLARE @InterestPaid MONEY, @InterestAccrued MONEYSELECT @InterestPaid = 0, @InterestAccrued = 0UPDATE #PmtsSET TotalInterestPaid = ISNULL(@InterestPaid, 0) + TotalInterestPaid ,TotalInterestAccrued = TotalInterestAccrued + @InterestAccrued ,@InterestPaid = ISNULL(Interest_paid, 0) + @InterestPaid ,@InterestAccrued = @InterestAccrued + Calc_interest_accruedSELECT * FROM #PmtsDROP TABLE #Pmts`Note that QU requires the CLUSTERED index on your date column and it will be much faster than any recursive approach to solving this problem.Even though it doesn't produce exactly the results you need, I'm hoping it puts you on the right track. My mantra: No loops! No CURSORs! No RBAR! Hoo-uh!My thought question: Have you ever been told that your query runs too fast?My advice:INDEXing a poor-performing query is like putting sugar on cat food. Yeah, it probably tastes better but are you sure you want to eat it?The path of least resistance can be a slippery slope. Take care that fixing your fixes of fixes doesn't snowball and end up costing you more than fixing the root cause would have in the first place.Need to UNPIVOT? Why not CROSS APPLY VALUES instead?Since random numbers are too important to be left to chance, let's generate some!Learn to understand recursive CTEs by example.Splitting strings based on patterns can be fast!My temporal SQL musings: Calendar Tables, an Easter SQL, Time Slots and Self-maintaining, Contiguous Effective Dates in Temporal Tables Jeff Moden SSC Guru Group: General Forum Members Points: 84973 Visits: 41071 dwain.c (10/28/2012)I'm thinking that you may have your interest accured and interest paid terminology a little mixed up here.Take a look at the following Quirky Update (QU) method for calculating what I think you need.`CREATE TABLE #Pmts (tran_date DATETIME PRIMARY KEY CLUSTERED ,Calc_interest_accrued MONEY, Interest_paid MONEY ,TotalInterestPaid MONEY, TotalInterestAccrued MONEY ,TotalInterestDue AS (TotalInterestAccrued - TotalInterestPaid))INSERT INTO #Pmts (tran_date, Calc_interest_accrued, Interest_paid ,TotalInterestPaid, TotalInterestAccrued)SELECT '2012-09-08',54.06,NULL,0,0UNION ALL SELECT '2012-09-10',54.06,NULL,0,0UNION ALL SELECT '2012-09-11',24.04,112.35,0,0UNION ALL SELECT '2012-09-13',23.67,20.12,0,0UNION ALL SELECT '2012-09-14',23.67,NULL,0,0DECLARE @InterestPaid MONEY, @InterestAccrued MONEYSELECT @InterestPaid = 0, @InterestAccrued = 0UPDATE #PmtsSET TotalInterestPaid = ISNULL(@InterestPaid, 0) + TotalInterestPaid ,TotalInterestAccrued = TotalInterestAccrued + @InterestAccrued ,@InterestPaid = ISNULL(Interest_paid, 0) + @InterestPaid ,@InterestAccrued = @InterestAccrued + Calc_interest_accruedSELECT * FROM #PmtsDROP TABLE #Pmts`Note that QU requires the CLUSTERED index on your date column and it will be much faster than any recursive approach to solving this problem.Even though it doesn't produce exactly the results you need, I'm hoping it puts you on the right track.Not quite right. You need to modify the update to have a FROM clause from the target table so that you can add the MAXDOP option to prevent parallelism. Like this...` UPDATE tgt SET TotalInterestPaid = ISNULL(@InterestPaid, 0) + TotalInterestPaid ,TotalInterestAccrued = TotalInterestAccrued + @InterestAccrued ,@InterestPaid = ISNULL(Interest_paid, 0) + @InterestPaid ,@InterestAccrued = @InterestAccrued + Calc_interest_accrued FROM #Pmts tgt WITH(TABLOCKX) OPTION (MAXDOP 1);`The TablockX isn't required on a Temp Table but it'll bypass all sorts of row escalation to make leaner (memory-wise) and faster code.I haven't checked the rest of the code nor have my changes made it solve the OP's precise problem. --Jeff ModenRBAR is pronounced ree-bar and is a Modenism for Row-By-Agonizing-Row.First step towards the paradigm shift of writing Set Based code: Stop thinking about what you want to do to a row... think, instead, of what you want to do to a column.If you think its expensive to hire a professional to do the job, wait until you hire an amateur. -- Red Adair Helpful Links:How to post code problemsHow to post performance problemsForum FAQs dwain.c SSCertifiable Group: General Forum Members Points: 7213 Visits: 6431 Jeff,Thanks for keeping me honest. I must be rusty from my holiday away to have forgotten the MAXDOP and TABLOCK.This should also work, no?`UPDATE #Pmts WITH(TABLOCK)SET TotalInterestPaid = ISNULL(@InterestPaid, 0) + TotalInterestPaid ,TotalInterestAccrued = TotalInterestAccrued + @InterestAccrued ,@InterestPaid = ISNULL(Interest_paid, 0) + @InterestPaid ,@InterestAccrued = @InterestAccrued + Calc_interest_accruedOPTION (MAXDOP 1)` My mantra: No loops! No CURSORs! No RBAR! Hoo-uh!My thought question: Have you ever been told that your query runs too fast?My advice:INDEXing a poor-performing query is like putting sugar on cat food. Yeah, it probably tastes better but are you sure you want to eat it?The path of least resistance can be a slippery slope. Take care that fixing your fixes of fixes doesn't snowball and end up costing you more than fixing the root cause would have in the first place.Need to UNPIVOT? Why not CROSS APPLY VALUES instead?Since random numbers are too important to be left to chance, let's generate some!Learn to understand recursive CTEs by example.Splitting strings based on patterns can be fast!My temporal SQL musings: Calendar Tables, an Easter SQL, Time Slots and Self-maintaining, Contiguous Effective Dates in Temporal Tables Jeff Moden SSC Guru Group: General Forum Members Points: 84973 Visits: 41071 Don't know. I've never tried it that way. I know the way I demonstrated works. Can't vouch for the way you showed at all. --Jeff ModenRBAR is pronounced ree-bar and is a Modenism for Row-By-Agonizing-Row.First step towards the paradigm shift of writing Set Based code: Stop thinking about what you want to do to a row... think, instead, of what you want to do to a column.If you think its expensive to hire a professional to do the job, wait until you hire an amateur. -- Red Adair Helpful Links:How to post code problemsHow to post performance problemsForum FAQs