FIX: Complex Distinct or Group By Query Can Return Unexpected Results with Parallel Execution Plan (276329)

SYMPTOMS

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.

RESOLUTION

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

Hotfix

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.

WORKAROUND

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.