Microsoft KB Archive/933724

= FIX: The query performance is slow when you run a query that uses a user-defined scalar function against an instance of SQL Server 2005 =

Article ID: 933724

Article Last Modified on 11/20/2007

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APPLIES TO


 * Microsoft SQL Server 2005 Standard 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 Developer Edition
 * Microsoft SQL Server 2005 Standard X64 Edition
 * Microsoft SQL Server 2005 Standard Edition for Itanium-based Systems Community Technology Preview

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Bug #: 50000964 (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 installing the hotfix package
 * Whether you must restart the computer after you install 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
Consider the following scenario. You have a query that uses a user-defined scalar function. You run the query against an instance of Microsoft SQL Server 2005. In this scenario, the query performance is slow.



CAUSE
This problem occurs because the SQL Server Database Engine query optimizer performs only a few optimizations for the query. This behavior occurs because many of the optimizations that the query optimizer performs are not safe. Therefore, the query optimizer uses an inefficient query plan for the query.



Cumulative update information
To resolve this problem, obtain the cumulative update package for SQL Server 2005 Service Pack 2 (build 3161). For more information about how to obtain the cumulative update package (build 3161), click the following article number to view the article in the Microsoft Knowledge Base:

935356 Cumulative update package (build 3161) for SQL Server 2005 Service Pack 2 is available

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
To apply this hotfix, you must have SQL Server 2005 Service Pack 2 (SP2) installed on the computer. 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.

Hotfix file information
The global 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 Database Engine, 32-bit version

SQL Server 2005 Database Engine, x64 version

SQL Server 2005 Database Engine, Itanium architecture 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
This problem does not occur in SQL Server 2000. SQL Server 2000 does not support nondeterministic system functions within a user-defined function.

After you apply this hotfix, you must turn on the new trace flag 4110 in SQL Server 2005. After you turn on this trace flag, SQL Server 2005 will not support nondeterministic system functions within a user-defined function. You can turn on trace flag 4110 by using the following command. DBCC TRACEON (4110) 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

For more information about the user-defined functions in SQL Server 2005, visit the following Microsoft Developer Network (MSDN) Web site:

http://msdn2.microsoft.com/en-us/library/ms190704.aspx

Keywords: kbbug kbfix kbqfe kbpubtypekc kbhotfixserver KB933724

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