Symptoms
Assume that you query a binary large object (BLOB) column in Microsoft SQL Server 2008 R2 or in Microsoft SQL Server 2012 on a computer that has multiple CPUs. The query uses the NOLOCKhint. In this situation, you experience high CPU usage on the computer.Note This issue is more likely to occur if the computer has 16 or more CPUs installed.
Cause
This issue occurs because a spinlock backoff algorithm is not efficient.
Resolution
Cumulative update information
Cumulative Update 2 for SQL Server 2012 SP1
The fix for this issue was first released in Cumulative Update 2. For more information about how to obtain this cumulative update package for SQL Server 2012 SP1, click the following article number to view the article in the Microsoft Knowledge Base:
2790947 Cumulative update package 2 for SQL Server 2012 Service Pack 1Note 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 2012 SP1 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:
2772858 The SQL Server 2012 builds that were released after SQL Server 2012 Service Pack 1 was released
Cumulative Update 5 for SQL Server 2012
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 2012, click the following article number to view the article in the Microsoft Knowledge Base:
2777772 Cumulative update package 5 for SQL Server 2012Note 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 2012 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:
2692828 The SQL Server 2012 builds that were released after SQL Server 2012 was released
SQL Server 2008 R2 Service Pack 2
The fix for this issue was first released in Cumulative Update 3. For more information about how to obtain this cumulative update package for SQL Server 2008 R2 Service Pack 2, click the following article number to view the article in the Microsoft Knowledge Base:
2754552 Cumulative update package 3 for SQL Server 2008 R2 Service Pack 2Note 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 Service Pack 2 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:
2730301 The SQL Server 2008 R2 builds that were released after SQL Server 2008 R2 Service Pack 2 was released
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Workaround
To work around the issue, use one of the following methods:
-
Decrease size of the binary large object column.
-
Remove the NOLOCKhint from the query.
-
Reduce the number of CPUs that SQL Server uses.
