DetailPage-MSS-KB

Microsoft small business knowledge base

Article ID: 948248 - Last Review: February 19, 2008 - Revision: 1.1

Bug: #50002369 (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, you have a table that contains a column of the bigint data type. You create statistics for the table in the bigint column. When you run a query that uses the statistics in the column, the performance decreases.

This problem occurs if one of the following conditions is true:
  • You create an index in the bigint column. The statistics are rebuilt later.
  • You manually create statistics in the bigint column by using the CREATE STATISTICS statement.
  • The statistics are created automatically because the AUTO_CREATE_STATISTICS option is set to ON.

CAUSE

The performance decreases because of an incorrect cardinality estimation that is derived from some incorrect information from the statistics. Inaccurate information is generated when SQL Server 2005 calculates the distance between the minimum value and the maximum value in a histogram.

RESOLUTION

The fix for this issue was first released in Cumulative Update 6. 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:
946608  (http://support.microsoft.com/kb/946608/LN/ ) Cumulative update package 6 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  (http://support.microsoft.com/kb/937137/LN/ ) 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 "Applies to" section.

MORE INFORMATION

After you apply this hotfix, you must enable trace flag 4124 to resolve this issue.

To determine whether you are encountering this problem, use the following methods:
  • Examine the output of the DBCC SHOW_STATISTICS statement. If the All Density column displays incorrect values of 1, you are encountering this problem.
  • Re-create the statistics by enabling the WITH FULLSCAN option in the CREATE STATISTICS statement. If the All Density column shows correct values, and if the performance does not decrease, you are not encountering this problem.
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:
946608  (http://support.microsoft.com/kb/946608/LN/ ) Cumulative update package 6 for SQL Server 2005 Service Pack 2

REFERENCES

For more information about the list of builds that are available after SQL Server Service Pack 2, click the following article number to view the article in the Microsoft Knowledge Base:
937137  (http://support.microsoft.com/kb/937137/LN/ ) The SQL Server 2005 builds that were released after SQL Server 2005 Service Pack 2 was released
For more information about the Incremental Servicing Model for SQL Server, click the following article number to view the article in the Microsoft Knowledge Base:
935897  (http://support.microsoft.com/kb/935897/LN/ ) An Incremental Servicing Model is available from the SQL Server team to deliver hotfixes for reported problems
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  (http://support.microsoft.com/kb/913089/LN/ ) How to obtain the latest service pack for SQL Server 2005
For more information about the new features and the improvements in SQL Server 2005 Service Pack 2, visit the following Microsoft Web site:
http://go.microsoft.com/fwlink/?LinkId=71711 (http://go.microsoft.com/fwlink/?LinkId=71711)
For more information about the naming schema for SQL Server updates, click the following article number to view the article in the Microsoft Knowledge Base:
822499  (http://support.microsoft.com/kb/822499/LN/ ) New naming schema for Microsoft SQL Server software update packages
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684  (http://support.microsoft.com/kb/824684/LN/ ) Description of the standard terminology that is used to describe Microsoft software updates

APPLIES TO
  • Microsoft SQL Server 2005 Standard Edition
  • Microsoft SQL Server 2005 Developer Edition
  • Microsoft SQL Server 2005 Enterprise 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
Keywords: 
kbsql2005engine kbhotfixrollup kbfix kbpubtypekc kbqfe kbexpertiseadvanced KB948248
Share
Additional support options
Ask The Microsoft Small Business Support Community
Contact Microsoft Small Business Support
Find Microsoft Small Business Support Certified Partner
Find a Microsoft Store For In-Person Small Business Support