Symptoms
When you run a query against a partitioned table in Microsoft SQL Server 2008 R2 or in Microsoft SQL Server 2012, an incorrect result returns intermittently. This issue occurs if the following conditions are true:
-
The size difference between the partitions of the table is large.
-
The query uses a high degree of parallelism in the query execution plan.
Note A high degree signifies that the max degree of parallelism (MAXDOP) option is set to a number that is greater than six.
Resolution
Cumulative update information
Cumulative update 6 for SQL Server 2012
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 2012, click the following article number to view the article in the Microsoft Knowledge Base:
2728897 Cumulative update package 6 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
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 4 for SQL Server 2008 R2 Service Pack 2 (SP2)
The fix for this issue was first released in Cumulative Update 4. 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:
2777358 Cumulative update package 4 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
Workaround
To work around this issue, run a query that uses a degree of parallelism of less than six.
Note The optimal MAXDOP value may vary. To make sure that you remove the problem, set the MAXDOP value to 1.Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.