Microsoft KB Archive/936185

= FIX: Blocking and performance problems may occur when you enable trace flag 1118 in SQL Server 2005 if the temporary table creation workload is high =

Article ID: 936185

Article Last Modified on 11/20/2007

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APPLIES TO


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

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Bug: #50001020 (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.



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 after you apply the hotfix package
 * The files that are contained in the hotfix package



SYMPTOMS
In Microsoft SQL Server 2005, you may notice blocking and performance-related problems. You experience this problem if the following conditions are true:
 * You enable trace flag 1118.
 * The temporary table creation workload is high.
 * Multiple data files exist for the tempdb database.

In the sysprocesses system table, the value in the waittype column of the tempdb database is set to PAGELATCH.



CAUSE
This problem occurs when multiple data files exist in the tempdb database. When these multiple data files exist, latch waits occur in the Shared Global Allocation Map (SGAM) pages of the tempdb database.



RESOLUTION
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
You must have Microsoft SQL Server 2005 Service Pack 2 (SP2) installed to apply this hotfix.

For more information about how to obtain SQL Server 2005 Service Pack 2, 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
You do not have to restart the computer after you apply this hotfix.

Registry information
You do not have to change the registry.

Hotfix file information
This hotfix contains only those files that are required to correct the issues that this article lists. This hotfix may not contain of 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, Itanium architecture version


WORKAROUND
To work around this problem, disable trace flag 1118. You can interactively disable the trace flag by using the following DBCC TRACEOFF command: DBCC TRACEOFF (1118, -1) You can also specify the trace flag as a startup parameter of the SQL Server service. When you specify the trace flag as a startup parameter, the trace flag is automatically enabled when the SQL Server service starts. If you set the trace flag as a startup parameter, you can still use the DBCC TRACEOFF command to disable the trace flag interactively.



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
The hotfix that this article describes affects only the tempdb database. Additionally, you do not have to have trace flag 1118 after you install this hotfix. However, you can still use trace flag 1118.



For more information, 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

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

328551 FIX: Concurrency enhancements for the tempdb database

Additional query words: 1118 trace flag

Keywords: kbqfe kbpubtypekc kbhotfixserver KB936185

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