FIX: The UPDATE CUBE MDX statement writes the remainder value of the writeback formula to a NULL cell (834491)

SYMPTOMS

In SQL Server 2000, when you use a weighted writeback formula in a Multidimensional Expressions (MDX) UPDATE CUBE statement, a small remainder may be left after the new value is allocated by using the specified formula. The remaining value is inserted in the writeback table for the last cell that is evaluated in the writeback set that the UPDATE CUBE statement specifies. If the last cell is NULL, the cell will still be updated with the remainder value. This behavior may cause records to be displayed for dimension members that were previously empty. Sometimes, the remainder value is so low that the client tool will display the value as zero (0).

For example, the following MDX UPDATE CUBE statement sets the 1998, Forecast, and General & Administrative expenses for the state of California to a value of $750,000. The new value is allocated to the individual stores in California based on their contribution to the total Current Year's Actual Gross Sales for California in the previous year.

UPDATE CUBE
[Budget] SET  
( [Category].[All Category].[Forecast],  
[Account].[All Account].[Net Income].[Total Expense].[General & Administration],
[Store].[All Stores].[USA].[CA], 
[Time].[1998],
[Measures].[Amount]  ) = 750000

USE_WEIGHTED_ALLOCATION BY 
iif(
IsEmpty(( ParallelPeriod([Time].[Year], 1, [Time].Currentmember), 
[Category].[All Category].[Current Year's Actuals], [Store].Currentmember, 
[Account].[All Account].[Net Income].[Net Sales].[Gross Sales], [Measures].[Amount])),
-- Sales Value is empty for the previous year so leave the new value as NULL.
NULL, 
-- Otherwise take the Current Years Actual Gross Sales for the current store, 
--divide it by the total for all of California to get the percentage contribution 
--of this store to Gross Sales and allocate that percentage of the new 
--General & Administration value to this store.
( ParallelPeriod([Time].[Year], 1, [Time].Currentmember) ,  
[Category].[All Category].[Current Year's Actuals], [Store].Currentmember, 
[Account].[All Account].[Net Income].[Net Sales].[Gross Sales], [Measures].[Amount] )    /  
([Time].[1997], [Category].[All Category].[Current Year's Actuals], 
[Store].[All Stores].[USA].[CA], [Account].[All Account].[Net Income].[Net Sales].[Gross Sales], [Measures].[Amount] )  )

Because Alameda has no value for the Gross Sales account in the Current Year's Actuals category for 1997, you would expect Alameda to have no General & Administration value assigned. However, if you run this UPDATE CUBE statement and then you run the following SELECT statement, the results show a value of 0.002 for Alameda:

SELECT
[Measures].Members   ON COLUMNS,
{ [Store].[All Stores].[USA].[CA],   Descendants([Store].[All Stores].[USA].[CA], [Store].[Store City])  } 
ON ROWS
FROM [Budget]
WHERE 
( [Category].[All Category].[Forecast], 
[Time].[1998] , 
[Account].[All Account].[Net Income].[Total Expense].[General & Administration] )

The following table displays the expected results:

	Amount
CA	750000
Alameda
Beverly Hills	215575.4595
Los Angeles	257017.7488
San Diego	256479.9204
San Francisco	20926.8713

The following table displays the actual results:

	Amount
CA	750000
Alameda	0.002
Beverly Hills	215575.4575
Los Angeles	257017.7488
San Diego	256479.9204
San Francisco	20926.8713

After you apply this fix, the remainder value will be applied to one of the cells in the writeback set.

   Date         Time   Version    Size       File name
   -------------------------------------------------------
   16-Jul-2004  01:51  8.0.960.0    221,760  Msmdcb80.dll
   16-Jul-2004  02:17  8.0.0.960  4,063,808  Msmddo80.dll
   16-Jul-2004  01:45  8.0.960.0  1,036,864  Msmdgd80.dll
   16-Jul-2004  01:39  8.0.960.0    172,608  Msmdpump.dll
   16-Jul-2004  02:27  8.0.0.960  9,642,564  Msmdsgn80.dll
   16-Jul-2004  01:40  8.0.960.0  1,839,684  Msmdsrv.exe
   16-Jul-2004  02:03  8.0.960.0  2,085,456  Msolap80.dll
   16-Jul-2004  01:17  8.0.960.0    446,524  Msmdsgn.rll
   16-Jul-2004  00:58  8.0.960.0    213,068  Msolap80.rll