Microsoft KB Archive/843262

= FIX: You may notice that the query performance on an Analysis Services cube degrades temporarily after an incremental update processes the virtual dimensions =

Article ID: 843262

Article Last Modified on 11/21/2006

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APPLIES TO


 * Microsoft SQL Server 2000 Analysis Services

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Bug #: 14362 (Plato7x)



SYMPTOMS
When you run a query on an Analysis Services cube that contains virtual dimensions, you may notice that the performance of the query degrades temporarily after the virtual dimensions are processed by using the incremental update processing.

This problem occurs if the version of SQL Server 2000 Analysis Services that is installed on your computer is 8.0.931 or later.



CAUSE
By default, virtual dimensions are changing dimensions. When a changing dimension that is used in an Analysis Services cube is processed, a lazy aggregation processing operation is triggered on a low-priority background thread.

After you install the 8.0.931 build version of SQL Server 2000 Analysis Services, when the virtual dimensions are processed by using the incremental update processing method, the lazy aggregation processing is triggered. During the lazy aggregation, the flexible aggregations and indexes for the Analysis Services cube that uses the changing dimensions are deleted and re-created. Therefore, the query performance may noticeably decrease until the lazy aggregation processing is complete.

Note Before hotfix build 8.0.931, when the virtual dimensions are processed by using the incremental update processing method, the lazy aggregation processing operation is not triggered.



Service pack information
To resolve this problem, obtain the latest service pack for Microsoft SQL Server 2000. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

290211 How to obtain the latest SQL Server 2000 service pack

Hotfix information
The English version of this hotfix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.   Date         Time   Version    Size       File name ---  06-Apr-2004  07:56                18,800  Msmd.h   09-Jun-2004  05:04  8.0.950.0    221,760  Msmdcb80.dll 09-Jun-2004 05:04  8.0.0.950  4,063,808  Msmddo80.dll 09-Jun-2004 05:04  8.0.950.0  1,032,768  Msmdgd80.dll 09-Jun-2004 05:04  8.0.950.0    172,608  Msmdpump.dll 09-Jun-2004 04:09  8.0.950.0    446,524  Msmdsgn.rll 09-Jun-2004 05:04  8.0.0.950  9,642,564  Msmdsgn80.dll 09-Jun-2004 05:04  8.0.950.0  1,839,684  Msmdsrv.exe 09-Jun-2004 05:04  8.0.950.0  2,081,360  Msolap80.dll 09-Jun-2004 03:55  8.0.950.0    213,068  Msolap80.rll Note Because of file dependencies, the most recent hotfix that contains these files may also contain additional files.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.

This problem was first corrected in Microsoft SQL Server 2000 Service Pack 4.



MORE INFORMATION
This update to Analysis Services introduces the prioritization of indexing of partitions in a cube during lazy processing. The introduction of this prioritization improves the efficiency of lazy processing. To prioritize the indexing of partitions in a cube during lazy processing, the Analysis Services program uses the value of the Description property of partitions. The Description property of a partition has the following characteristics:
 * The value of the Description property is a string that is considered as case insensitive.
 * By default, the Description property is not set for a partition. Therefore, to assign the priority, you must modify the value of the Description property of the partition.
 * The value of the Description property is sorted based on the lexicographic order. The partition that has the highest value for the Description property is processed first. For example, if you have two partitions,  and , and you assign the value of the Description property for   as 001 and you assign the value of the Description property for   as 002, the Analysis Services program will process the partition   first.
 * If two partitions have same value for the Description property, the order among the conflicting partitions is decided by the Analysis Services program.
 * If the Description property is not set for a partition, the partition is processed after all other partitions that have the Description property set have been processed.

The following code sample can be used to assign a value to the Description property of a partition.

Notes
 * This code sample uses the syntax of the Microsoft Visual Basic 6.0 programming language and sets the Description property value of the partition HR in the cube HR of the sample database FoodMart 2000 to &quot;001&quot;.
 * Before you run this code sample, you must replace  with the name of your Analysis Server.
 * Before you run this code sample, you must add a reference to the Microsoft Decision Support Objects library.

Dim s As New DSO.Server

'Connect to the Analysis Server. s.Connect &quot;AnalysisServer&quot;

'Instantiate the data source. Dim database As MDStore Set database = s.MDStores(&quot;Foodmart 2000&quot;)

'Instantiate the cube. Dim cube As MDStore Set cube = database.MDStores(&quot;HR&quot;)

'Instantiate the partition. Dim partition As MDStore Set partition = cube.MDStores(&quot;HR&quot;)

'Set the Description property value of the partition. partition.Description = &quot;001&quot;

'Update the partition. partition.Update

