FIX: A query that performs join operations between multiple tables may return incorrect results

View products that this article applies to.

BUG #: 364392

(SQL Server 8.0)

SYMPTOMS

When you run a query that performs join operations between multiple tables, the query may return incorrect results. You may see this behavior when the SQL Server query optimizer recognizes the query as a candidate for an internal join strategy known as a star join, and it chooses the star join strategy to perform the join on the tables in the query.

Back to the top

WORKAROUND

To work around this problem, create a temporary table to store the intermediary results or to store the complex aggregations that are based on several joins on the large table. Then, join the other tables with the temporary table. This may prevent the SQL Server query optimizer from using the star join strategy for joining the tables in the query. This, in turn, may cause the query to return the correct results.

Back to the top

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 (http://support.microsoft.com/kb/290211/ ) How to obtain the latest SQL Server 2000 service pack

Back to the top

Hotfix information

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         Time   Version         Size       File name
   ----------------------------------------------------------------------
   29-Jan-2003  11:48  7.0.9466.0        344,064  Msvcr70.dll      
   29-Jan-2003  11:48  2000.80.722.0      57,904  Osql.exe         
   29-Jan-2003  11:48  2000.80.534.0     127,548  Sqdedev.dll      
   29-Jan-2003  11:48  2000.80.194.0     180,290  Sqlunirl.dll     
   25-Feb-2003  14:11  2000.80.777.0      29,244  Dbmslpcn.dll     
   07-Feb-2003  16:14                    786,432  Distmdl.ldf
   07-Feb-2003  16:14                  2,359,296  Distmdl.mdf
   29-Jan-2003  12:25                        180  Drop_repl_hotfix.sql
   31-Jan-2003  11:02  2000.80.763.0   1,557,052  Dtsui.dll        
   29-Jan-2003  15:48                    746,470  Instdist.sql
   29-Jan-2003  12:25                      1,402  Inst_repl_hotfix.sql
   07-Feb-2003  17:10  2000.80.765.0      90,692  Msgprox.dll      
   07-Feb-2003  14:23                  1,065,895  Replmerg.sql
   07-Feb-2003  17:10  2000.80.765.0     221,768  Replprov.dll     
   07-Feb-2003  17:10  2000.80.765.0     307,784  Replrec.dll      
   06-Mar-2003  15:32                  1,084,369  Replsys.sql
   03-Mar-2003  03:48                    104,958  Sp3_serv_uni.sql
   19-Mar-2003  04:50  2000.80.789.0      28,672  Sqlevn70.rll
   27-Feb-2003  12:04  2000.80.778.0     176,696  Sqlmap70.dll     
   07-Feb-2003  17:10  2000.80.765.0      57,920  Sqlrepss.dll     
   19-Mar-2003  04:54  2000.80.789.0   7,540,820  Sqlservr.exe     
   07-Feb-2003  17:10  2000.80.765.0      45,644  Sqlvdi.dll       
   25-Feb-2003  14:11  2000.80.777.0      29,244  Ssmslpcn.dll     
   25-Feb-2003  14:11  2000.80.777.0      82,492  Ssnetlib.dll     
   17-Mar-2003  01:19                    727,132  Sysmessages.sym
   27-Feb-2003  12:04  2000.80.778.0      98,872  Xpweb70.dll

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

Back to the top

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section of this article.This problem was first corrected in Microsoft SQL Server 2000 Service Pack 4.

Back to the top

MORE INFORMATION

This problem does not occur with all queries that perform joins between multiple tables. The SQL Server query optimizer chooses the join strategy after it analyzes the indexes and the references for the joined tables that are in the query. The SQL Server query optimizer choses a star join strategy only if the star join is considered the most optimal join strategy. Therefore, this problem will not occur with most queries that involve joins between multiple tables because a star join is not a common strategy for the SQL Server query optimizer to use.

However, the execution plan of a query does not provide any information about whether the SQL Server query optimizer chose the star join strategy to join the tables in the query.

Back to the top