Microsoft KB Archive/311104

= FIX: The SELECT Statement with Parallelism Enabled May Cause an Assertion =

Article ID: 311104

Article Last Modified on 10/12/2005

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APPLIES TO


 * Microsoft SQL Server 2000 Standard Edition

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This article was previously published under Q311104



BUG #: 355925 (SHILOH_BUGS)



SYMPTOMS
The following assertion may occur if you run a SELECT statement on a multiprocessor computer where SQL Server permits parallel plan generation:   Short Stack Dump 00866627 Module(sqlservr+00466627) (CStackDump::GetContextAndDump+0000002E) 0086804E Module(sqlservr+0046804E) (stackTrace+0000021D) 0091D108 Module(sqlservr+0051D108) (utassert_fail+000002E3) 006ED026 Module(sqlservr+002ED026) CQScanXProducer::GetBitmapData+0000007D)  006EC60E Module(sqlservr+002EC60E) (CQScanXProducer::Open+00000094)   006EC1FD Module(sqlservr+002EC1FD) (FnProducerThread+0000020E)   0053C403 Module(sqlservr+0013C403) (subproc_main+000000C2)   41073379 Module(UMS+00003379) (ProcessWorkRequests+0000024A)   41073071 Module(UMS+00003071) (ThreadStartRoutine+000000BD)   7800A27B Module(MSVCRT+0000A27B) (beginthread+000000CE)   77E8758A Module(KERNEL32+0000758A) (SetFilePointer+0000018A)   ---   2001-10-18 13:45:09.57 spid54    SQL Server Assertion: File: qsxchng.cpp, line=2104    Failed Assertion = 'pbmData->FCompleted == fTrue'.   2001-10-18 13:45:09.58 spid54    Error: 3624, Severity: 20, State: 1. Check your SQL Server error log file for this assertion.



RESOLUTION
A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Microsoft SQL Server 2000 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The typical support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The English version of this fix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.   Date          Version      Size                File name

OCT-08-02    8.00.690     7,467,092 bytes     Sqlservr.exe

NOTE: Because of file dependencies, the most recent hotfix or feature that contains the files may also contain additional files.



WORKAROUND
To work around this problem, use one of the following methods:
 * Add the OPTION (MAXDOP 1) to the SELECT statement to disable parallel plan generation for the query.

-or-
 * Set the max degree of parallelism configuration option to 1. If you set max degree of parallelism to a value of 1, this suppresses parallel plan generation for all queries that are run on the server.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

Microsoft is researching this problem and will post more information in this article when the information becomes available.