FIX: Poor performance and some occasional non-yielding scheduler errors occur when you create a complex view that references a large amount of nested views or tables in SQL Server 2008 or in SQL Server 2008 R2

When you create a complex view in SQL Server 2008 or in SQL Server 2008 R2, poor performance and some occasional non-yielding scheduler errors occur. This issue usually occurs when the CREATE VIEW statement references a large amount of nested views or tables.

For example, a SELECT statement of the CREATE VIEW statement uses up to 400 tables or more at a time, and selects 87 columns from each of those tables.

This issue occurs because the SQL Server code base performs string comparison directly by the object names.

When the complex module Data Definition language (DDL) statement runs, SQL Server has to build a dependency list of the objects involved. However, the SQL Server code base performs string comparisons directly for the object names. Therefore, CPU starvation occurs for the other worker threads that run on the same scheduler, and a non-yielding scheduler error occurs.

Cumulative update information

SQL Server 2008 R2

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 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:

SQL Server 2008 Service Pack 1

The fix for this issue was first released in Cumulative Update 10 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: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: 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.

SQL Server 2008 Service Pack 2

The fix for this issue was first released in Cumulative Update 1 for SQL Server 2008 Service Pack 2. For more information about 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 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:

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

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: 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: For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base: