FIX: Performance might be slow when you run a parallel query against a table that has a large amount of spatial data in SQL Server 2008 R2

Microsoft distributes Microsoft SQL Server 2008 R2 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 R2 fix release.

Consider the following scenario:

• You run an instance of SQL Server 2008 R2 on a computer that has more than one processor.
• You run a parallel query against a table that has a large amount of spatial data.

In this scenario, SQL Server 2008 R2 might take a long time to run the query.

Note The issue might occur in one of the following situations:

• You set the MAXDOP query hint option to a value that is greater than 2.
• You set the Max Degree of Parallelism option to a value that is greater than 2 in server configuration.
  
  

This issue occurs because the spatial index is not used in the query plan.

Cumulative update information

SQL Server 2008 R2 Service Pack 1

The fix for this issue was first released in Cumulative Update 3 for SQL Server 2008 R2 Service Pack 1. For more information about how to obtain this cumulative update package, click the following article number to view the article in the Microsoft Knowledge Base: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 R2 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:

SQL Server 2008 R2

The fix for this issue was first released in cumulative update package 9. For more information about how to obtain this cumulative update package for SQL Server 2008 R2, click the following article number to view the article in the Microsoft Knowledge Base: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 R2 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:

To work around this issue, use one of the following methods:

• Use the spatial index hint option in the query.
• Disable the parallel execution plan option for the query.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For more information about parallel query processing, visit the following MSDN website: