FIX: Complex Distinct or Group By Query Can Return Unexpected Results with Parallel Execution Plan

Article translations Article translations
Article ID: 276329 - View products that this article applies to.
This article was previously published under Q276329
BUG #: 236325 (SHILOH_BUGS)
Expand all | Collapse all

On This Page


If all of the following conditions are true about a complex query, it is possible to receive unexpected results:
  • The query contains a DISTINCT clause or a GROUP BY clause that is implemented by using distinct operations.

  • The query contains multiple subqueries.

  • The execution plan contains parallel execution steps as well as a serial execution nested loops join.


To resolve this problem, obtain the latest service pack for Microsoft SQL Server 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
290211 INF: How to Obtain the Latest SQL Server 2000 Service Pack


NOTE: The following hotfix was created prior to Microsoft SQL Server 2000 Service Pack 1.

The English version of this fix should have the following file attributes or later:
   File name   Platform

   s80211i.exe  x86   
NOTE: Due to file dependencies, the most recent hotfix or feature that contains the preceding files may also contain additional files.


Prevent either the query or SQL Server from using the parallel execution plans by using either the MAXDOP 1 hint on the query or by changing the max degree of parallelism sp_configure setting to the value 1.


Microsoft has confirmed that this is a problem in Microsoft SQL Server 2000. This problem was first corrected in SQL Server 2000 Service Pack 1.


Article ID: 276329 - Last Review: November 5, 2003 - Revision: 3.1
  • Microsoft SQL Server 2000 Standard Edition
kbbug kbfix kbqfe kbsqlserv2000sp1fix KB276329

Give Feedback


Contact us for more help

Contact us for more help
Connect with Answer Desk for expert help.
Get more support from