FIX: An Outer or Semi JOIN Query That Results in Hash Role Reversal Followed by a Spill May Return Incorrect Results (824028)


The information in this article applies to:

  • 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 Enterprise Evaluation Edition
  • Microsoft SQL Server 2000 Workgroup Edition
  • Microsoft SQL Server 2000 Desktop Engine (MSDE)
  • Microsoft SQL Server 2000 Developer Edition 64 bit
  • Microsoft SQL Server 2000 Enterprise Edition 64-bit
SHILOH_BUGS:469823

SHILOH_BUGS:362535

SYMPTOMS

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.

MORE INFORMATION

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.

RESOLUTION

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.

WORKAROUND

To work around this problem, add an "OPTION (LOOP JOIN, MERGE JOIN)" query hint to the affected query.

STATUS

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.

MORE INFORMATION

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

Modification Type:MinorLast Reviewed:10/25/2005
Keywords:kbHotfixServer kbQFE kbQFE kbSQLServ2000preSP4fix kbfix kbbug KB824028
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