Microsoft KB Archive/317223

= FIX: Performance Slows If You Process More Than Two Partitions In Parallel =

Article ID: 317223

Article Last Modified on 2/22/2007

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APPLIES TO


 * Microsoft SQL Server 2000 Analysis Services

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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:

http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

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.

Additional query words: OLAP QFE HOTFIX parallel partition processing

Keywords: kbbug kbfix kbqfe KB317223

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