FIX: A performance issue occurs when you run a full-text query that contains the "AND NOT" clause in SQL Server 2008

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Microsoft distributes Microsoft SQL Server 2008 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 2008 fix release.
Symptoms
In Microsoft SQL Server 2008, a full-text query on a large table that contains a lot of rows takes much longer to finish than in SQL Server 2005. This problem occurs if the following conditions are true:
  • You set up a full-text index on the table.
  • The full-text query contains the “AND NOT” clause. For example, the query contains the following condition:
    <Condition 1> AND NOT <Condition 2>
Cause
This problem occurs because the execution plan for the query is not optimized. In the example that the "Symptoms" section mentions, the query is executed as two separate queries. The first query runs for Condition 1. The second query runs for Condition 2. In SQL Server 2008, these two queries are executed concurrently. Therefore, the second query runs very slowly and generates a very large result set. This execution plan causes a performance issue.

Note In SQL Server 2005, the second query is executed based on the result set that is generated by the first query. Because the first query generates a small result set, the performance of the same full-text query in SQL Server 2005 is faster than in SQL Server 2008
Resolution

Cumulative update information

The release version of SQL Server 2008

Important You must install this cumulative update package if your computer is running the release version of SQL Server 2008.

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 2008, click the following article number to view the article in the Microsoft Knowledge Base:
969531 Cumulative update package 5 for SQL Server 2008
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 2008 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:
956909 The SQL Server 2008 builds that were released after SQL Server 2008 was released

SQL Server 2008 Service Pack 1

Important You must install this cumulative update package if your computer is running SQL Server 2008 Service Pack 1.

The fix for this issue was also later released in Cumulative Update 3 for SQL Server 2008 Service Pack 1. For more information about this cumulative update package, click the following article number to view the article in the Microsoft Knowledge Base:
971491 Cumulative update package 3 for SQL Server 2008 Service Pack 1
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 2008 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:
970365 The SQL Server 2008 builds that were released after SQL Server 2008 Service Pack 1 was released
Microsoft SQL Server 2008 hotfixes are created for specific SQL Server service packs. You must apply a SQL Server 2008 Service Pack 1 hotfix to an installation of SQL Server 2008 Service Pack 1. 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.
References
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 An Incremental Servicing Model is available from the SQL Server team to deliver hotfixes for reported problems
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:
822499New 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 Description of the standard terminology that is used to describe Microsoft software updates
Properties

Article ID: 970287 - Last Review: 01/16/2015 03:47:00 - Revision: 3.0

  • Microsoft SQL Server 2008 Standard
  • Microsoft SQL Server 2008 Enterprise
  • Microsoft SQL Server 2008 Developer
  • Microsoft SQL Server 2008 Workgroup
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