Microsoft KB Archive/926515

= FIX: You may receive unexpected results when you run an MDX query in SQL Server 2005 Analysis Services =

Article ID: 926515

Article Last Modified on 11/4/2007

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APPLIES TO


 * Microsoft SQL Server 2005 Analysis Services

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Bug #: 50000370 (SQL Hotfix)



Notice
Microsoft distributes Microsoft SQL Server 2005 fixes as one downloadable file. Because the fixes are cumulative, each new release contains all the hotfixes and all the security fixes that were included with the previous SQL Server 2005 fix release.



SUMMARY
This article describes the following about this hotfix release:
 * The issues that are fixed by this hotfix package
 * The prerequisites for applying the hotfix package
 * Whether you must restart the computer after you apply the hotfix package
 * Whether the hotfix package is replaced by any other hotfix package
 * Whether you must make any registry changes
 * The files that are contained in the hotfix package



SYMPTOMS
When you run a Multidimensional Expressions (MDX) query in Microsoft SQL Server 2005 Analysis Services, you may receive unexpected results. This problem occurs if the MDX query accesses the desired fact or aggregation records by using the bitmap indexes for one or more dimensions that are involved in the query.



CAUSE
This problem occurs because SQL Server 2005 Analysis Services contains several I/O optimizations that allow for multiple segments of data in a single partition to be read in parallel. In some cases, this aspect of SQL Server 2005 Analysis Services may result in the data for segments being returned in a different order than the order in which they exist in the data file.

Although this situation helps in most scenarios, it can cause problems when the server is building indexes for a partition. The situation can cause problems because the index-building operation requires segment data to be returned in sequential order. The problem that is described in the &quot;Symptoms&quot; section occurs when the index-building operation does not enforce the sequential ordering of segments for a partition.



Hotfix information
A supported hotfix is now available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. To create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Prerequisites
No prerequisites are required to apply the original release version of this hotfix. To apply the Service Pack 1 version of this hotfix, you must have SQL Server 2005 Service Pack 1 installed. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

913089 How to obtain the latest service pack for SQL Server 2005

Restart information
Generally, you do not have to restart the computer after you apply this hotfix. However, you may have to restart the computer after you apply this hotfix if Windows Installer must replace files that are being used. Therefore, we recommend that you exit all SQL Server Analysis Services tools and clients. These tools and clients include Microsoft Internet Information Services if the computer is configured to provide HTTP access. Also, if you are installing this hotfix on a named instance of Microsoft SQL Server, we recommend that you stop the SQL Browser service before you apply this hotfix.

Hotfix replacement information
This hotfix does not replace any other hotfixes.

Registry information
You do not have to change the registry.

File information
This hotfix contains only those files that are required to correct the issues that this article describes. This hotfix may not contain all the files that you must have to fully update a product to the latest build.

The English version of this hotfix has the file attributes (or later file attributes) 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 item in Control Panel.

SQL Server 2005 SP1, x64-based version


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



MORE INFORMATION
To determine whether you are encountering this problem when an MDX query returns unexpected results, follow these steps:
 * 1) Run the query, and then note the unexpected results.
 * 2) Change the value of the IndexUseEnabled parameter in the Query section of the Msmdsrv.ini file.
 * 3) Restart the SQL Server 2005 Analysis Services server.
 * 4) Run the query again. If the results are correct, you are encountering the problem that is described in this article. If the results are still incorrect, you may be encountering another issue.

This problem does not apply to queries that involve partitions that contain a Distinct Count aggregate function for a measure in the measure group. This problem does not apply to such queries because the ordering of segment data reads is always enforced for Distinct Count measure groups. Because the Process Index option for a cube rebuilds only those indexes that are currently not present and does not rebuild existing indexes, we recommend that you fully reprocess all cubes after you apply this hotfix. By taking this action, you can make sure that all indexes are correctly built.

For more information about the naming schema for Microsoft SQL Server updates, click the following article number to view the article in the Microsoft Knowledge Base:

822499 New naming schema for Microsoft SQL Server software update packages

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Keywords: kbhotfixserver kbqfe kbpubtypekc KB926515

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