FIX: Performance Slows If You Process More Than Two Partitions In Parallel (317223)



The information in this article applies to:

  • Microsoft SQL Server 2000 Analysis Services

This article was previously published under Q317223
BUG #: 12578 (plato7x)

SYMPTOMS

If you process more than two (2) cube partitions in parallel on an Analysis Services server, the average number of rows processed per second is lower than that seen when you process two partitions in parallel or when a single cube partition is processed.

CAUSE

You can define dimension member keys based on character or string values in Microsoft SQL Server 2000 Analysis Services. During Analysis Services cube or partition processing, Analysis Services compares the dimension columns in the fact table against the dimension member keys.

String dimension member keys require a string comparison with the column from the fact table. Analysis Services uses a string comparison library that contains a critical section. The critical section can become a bottleneck when you process multiple cubes or partitions in parallel.

RESOLUTION

This fix resolves the bottleneck within the string comparison by removing the critical section. However, string comparisons are still considerably slower than integer or numeric comparisons. Therefore, Microsoft strongly recommends that you define dimension keys on integer or numeric columns from the source database.

A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next SQL Server service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The typical support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The English version of this fix should have the following file attributes or later:
   Date         Time          Version        Size  File name   
   ----------------------------------------------------------------
   03-JAN-2002  19:04       8.0.562.0     213,572  Msmdcb80.dll
   23-JAN-2002  00:59       8.0.571.0   1,315,396  Msmdvldm.exe
   19-MAR-2002  13:57       8.0.0.601   4,043,328  Msmddo80.dll
   19-MAR-2002  13:56       8.0.601.0   1,008,192  Msmdgd80.dll
   19-MAR-2002  12:53       8.0.601.0   1,774,148  Msmdsrv.exe
   19-MAR-2002  13:57       8.0.601.0   2,024,016  Msolap80.dll
   18-APR-2001  00:23   2000.80.382.0     815,676  Sqldata.dll
   19-MAR-2002  13:56   2000.80.534.0     590,396  Sqlsort.dll
				
NOTE: Due to file dependencies, the most recent hotfix or feature that contains the preceding files may also contain additional files.

WORKAROUND

To workaround this problem, use either integer or numeric columns for the dimension member keys.

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

Modification Type:MinorLast Reviewed:10/7/2005
Keywords:kbbug kbfix kbQFE KB317223