Microsoft KB Archive/938672

= FIX: When you populate a full-text index on a table that has a composite clustered index in SQL Server 2005, the population operation may be very slow =

Article ID: 938672

Article Last Modified on 9/4/2007

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APPLIES TO


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

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Bug #: 50001203 (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
Consider the following scenario. In Microsoft SQL Server 2005, a table has a composite clustered index. The first column in the clustered index definition is less selective than another column that is used in a unique index key. In this scenario, the population operation may be very slow when you populate a full-text index.



CAUSE
When you populate a full-text index, the full-text engine always crawls on the clustered index key. The clustered index key is used even if the table has other unique index key that the full-text engine can use to populate the full-text index to obtain better performance.



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.



WORKAROUND
To work around this issue, follow these steps:  Drop the clustered index.

You can use the DROP INDEX statement to drop a clustered index. For more information about the DROP INDEX statement, visit the following Microsoft Developer Network (MSDN) Web site:

http://msdn2.microsoft.com/en-us/library/aa258837(SQL.80).aspx

 Create a new clustered index on the column that is in the unique index key.

You can use the CREATE INDEX statement to create a clustered index. For more information about the CREATE INDEX statement, visit the following MSDN Web site:

http://msdn2.microsoft.com/en-us/library/ms188783.aspx





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
After you apply this hotfix, you must enable trace flag 7608 to enable this hotfix.

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

