Microsoft KB Archive/945770

= FIX: The DBCC CHECKDB statement takes longer to run on an x64-based computer than the statement takes to run on a 32-bit computer when you run the statement against a database in SQL Server 2005 =

Article ID: 945770

Article Last Modified on 12/11/2007

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

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Bug: #50002112 (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. You have an instance of Microsoft SQL Server 2005 that is installed on an x64-based computer. You run the DBCC CHECKDB statement against a database. In this scenario, the statement takes longer to run than it takes to run on a 32-bit computer.

Note This issue also occurs when you run the DBCC CHECKTABLE statement and the DBCC CHECKFILEGROUP statement.



CAUSE
This issue occurs because of the data purity checks that are introduced in SQL Server 2005.



RESOLUTION
The fix for this issue was first released in Cumulative Update 5. 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:

943656 Cumulative update package 5 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. We recommend 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:
 * 1) Back up the database from the x64-based computer.
 * 2) Restore the database on a 32-bit computer.
 * 3) Run the check statement against the database on the 32-bit computer.



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 can turn off the data purity checks when you run check statements. You can do this by enabling trace flag 2566. To enable the trace flag, run the following statement. DBCC TRACEON (2566,-1)

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:

943656 Cumulative update package 5 for SQL Server 2005 Service Pack 2

