FIX: An Outer or Semi JOIN Query That Results in Hash Role Reversal Followed by a Spill May Return Incorrect Results

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When you run a complex OUTER or SEMI JOIN query that involves hash joins on large data sets, or data sets that involve skewed distributions, you may receive incorrect results if the following conditions are true:
  • SQL Server (in rare circumstances) decides to reverse the roles of the hash build and probe inputs.
  • Subsequently, because the original build input is too large to fit in memory, it is spilled to disk.
  • Finally, the role reversal is undone.
To validate the applicability of this fix to your scenario, check the following:
  • Use SQL Profiler and capture the EventClass Execution Plan. Check to see if the query that is resulting in incorrect results is using the HASH operator.
  • Use SQL Profiler and capture the EventClass Hash Warning and confirm that this event is raised. If so, make sure that the data column EventSubClass contains "Hash Recursion" (indicates spilling). For more information, see the "Errors and Warnings Event Classes" topic in SQL Server Books Online.

Service pack information

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 How to obtain the latest SQL Server 2000 service pack

Hotfix information

The English version of this hotfix has the file attributes (or later file attributes) 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         Time   Version         Size             File name   ---------------------------------------------------------------------------   31-May-2003  18:45  2000.80.818.0      78,400 bytes  Console.exe         25-Jun-2003  01:01  2000.80.818.0      33,340 bytes  Dbmslpcn.dll        25-Apr-2003  02:12                    786,432 bytes  Distmdl.ldf   25-Apr-2003  02:12                  2,359,296 bytes  Distmdl.mdf   30-Jan-2003  01:55                        180 bytes  Drop_repl_hotfix.sql   23-Jun-2003  22:40  2000.80.837.0   1,557,052 bytes  Dtsui.dll           23-Jun-2003  22:40  2000.80.837.0     639,552 bytes  Dtswiz.dll          24-Apr-2003  02:51                    747,927 bytes  Instdist.sql   03-May-2003  01:56                      1,581 bytes  Inst_repl_hotfix.sql   08-Feb-2003  06:40  2000.80.765.0      90,692 bytes  Msgprox.dll         01-Apr-2003  02:07                      1,873 bytes  Odsole.sql   05-Apr-2003  01:46  2000.80.800.0      62,024 bytes  Odsole70.dll        07-May-2003  20:41  2000.80.819.0      25,144 bytes  Opends60.dll        02-Apr-2003  21:48  2000.80.796.0      57,904 bytes  Osql.exe            02-Apr-2003  23:15  2000.80.797.0     279,104 bytes  Pfutil80.dll        22-May-2003  22:57                     19,195 bytes  Qfe469571.sql   12-Jun-2003  16:37                  1,083,989 bytes  Replmerg.sql   04-Apr-2003  21:53  2000.80.798.0     221,768 bytes  Replprov.dll        08-Feb-2003  06:40  2000.80.765.0     307,784 bytes  Replrec.dll         05-May-2003  00:05                  1,085,874 bytes  Replsys.sql   01-Jun-2003  01:01  2000.80.818.0     492,096 bytes  Semobj.dll          31-May-2003  18:27  2000.80.818.0     172,032 bytes  Semobj.rll   29-May-2003  00:29                    115,944 bytes  Sp3_serv_uni.sql   01-Jun-2003  01:01  2000.80.818.0   4,215,360 bytes  Sqldmo.dll          07-Apr-2003  17:44                     25,172 bytes  Sqldumper.exe       19-Mar-2003  18:20  2000.80.789.0      28,672 bytes  Sqlevn70.rll   02-Jul-2003  00:18  2000.80.834.0     180,736 bytes  Sqlmap70.dll        08-Feb-2003  06:40  2000.80.765.0      57,920 bytes  Sqlrepss.dll        07-Jul-2003  17:57  2000.80.839.0   7,549,009 bytes  Sqlservr.exe        08-Feb-2003  06:40  2000.80.765.0      45,644 bytes  Sqlvdi.dll          25-Jun-2003  01:01  2000.80.818.0      33,340 bytes  Ssmslpcn.dll        01-Jun-2003  01:01  2000.80.818.0      82,492 bytes  Ssnetlib.dll        01-Jun-2003  01:01  2000.80.818.0      25,148 bytes  Ssnmpn70.dll        01-Jun-2003  01:01  2000.80.818.0     158,240 bytes  Svrnetcn.dll        31-May-2003  18:59  2000.80.818.0      76,416 bytes  Svrnetcn.exe        30-Apr-2003  23:52  2000.80.816.0      45,132 bytes  Ums.dll             02-Jul-2003  00:19  2000.80.834.0      98,816 bytes  Xpweb70.dll      				
Note Because of file dependencies, the most recent hotfix or feature that contains the files may also contain additional files.

To work around this problem, add an "OPTION (LOOP JOIN, MERGE JOIN)" query hint to the affected query.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.This problem was first corrected in Microsoft SQL Server 2000 Service Pack 4.
For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates

Article ID: 824028 - Last Review: 02/27/2014 18:44:28 - Revision: 8.4

  • Microsoft SQL Server 2000 Developer Edition
  • Microsoft SQL Server 2000 Standard Edition
  • Microsoft SQL Server 2000 Enterprise Edition
  • Microsoft SQL Server 2000 Personal Edition
  • Microsoft SQL Server 2000, Workgroup Edition
  • Microsoft SQL Server 2000 Desktop Engine (Windows)
  • Microsoft SQL Server 2000 Enterprise Edition 64-bit
  • kbnosurvey kbarchive kbhotfixserver kbqfe kbqfe kbsqlserv2000presp4fix kbfix kbbug KB824028