Microsoft KB Archive/940945

= FIX: Performance is very slow when the same stored procedure is executed at the same time in many connections on a multiple-processor computer that is running SQL Server 2005 =

Article ID: 940945

Article Last Modified on 11/20/2007

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APPLIES TO


 * Microsoft SQL Server 2005 Standard Edition
 * Microsoft SQL Server 2005 Developer Edition
 * Microsoft SQL Server 2005 Enterprise Edition
 * Microsoft SQL Server 2005 Enterprise X64 Edition
 * Microsoft SQL Server 2005 Enterprise Edition for Itanium-based Systems
 * Microsoft SQL Server 2005 Standard X64 Edition
 * Microsoft SQL Server 2005 Standard Edition for Itanium-based Systems
 * Microsoft SQL Server 2005 Workgroup Edition

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Bug #: 50001529 (SQL Hotfix)



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.



SYMPTOMS
You have a multiple-processor computer that is running Microsoft SQL Server 2005. Additionally, SQL Server 2005 is not running non-uniform memory access (NUMA) mode. When the same stored procedure is executed at the same time in many connections, the performance of SQL Server is very slow. If you examine the Batch Requests/sec counter of the SQL Statistics performance object in System Monitor (Perfmon.exe), the throughput of the counter decreases when this issue occurs. If you query the sys.dm_os_wait_stats dynamic management view when this issue occurs, you find many waits of the CMEMTHREAD wait type.



RESOLUTION
The fix for this issue was first released in Cumulative Update 3. For more information about how to obtain this cumulative update package for SQL Server 2005 Service Pack 2, click the following article number to view the article in the Microsoft Knowledge Base:

939537 Cumulative update package 3 for SQL Server 2005 Service Pack 2

Note Because the builds are cumulative, each new fix release contains all the hotfixes and all the security fixes that were included with the previous SQL Server 2005 fix release. Microsoft recommends that you consider applying the most recent fix release that contains this hotfix. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

937137 The SQL Server 2005 builds that were released after SQL Server 2005 Service Pack 2 was released

Microsoft SQL Server 2005 hotfixes are created for specific SQL Server service packs. You must apply a SQL Server 2005 Service Pack 2 hotfix to an installation of SQL Server 2005 Service Pack 2. By default, any hotfix that is provided in a SQL Server service pack is included in the next SQL Server service pack.



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
For more information about what files are changed, and for information about any prerequisites to apply the cumulative update package that contains the hotfix that is described in this Microsoft Knowledge Base article, click the following article number to view the article in the Microsoft Knowledge Base:

939537 Cumulative update package 3 for SQL Server 2005 Service Pack 2

