FIX: A Deadlock Occurs If You Run an Explicit UPDATE STATISTICS Command

View products that this article applies to.

BUG #: 470125 (SHILOH_BUGS)

SYMPTOMS

If you run an explicit UPDATE STATISTICS command against the same table from two different connections at the same time, the two connections may deadlock. One of the connections receives the following error message, and its UPDATE STATISTICS command is canceled:

Server: Msg 1205, Level 13, State 50, Line 3
Transaction (Process ID 52) was deadlocked on lock resources with another process and has been chosen as the deadlock victim. Rerun the transaction.

Deadlocks and their accompanying 1205 errors are not unique to this situation. Deadlocks may also occur in many other, unrelated scenarios. If you enable trace flag 1204 to capture more details about this particular deadlock, you see the two connections deadlocked on clustered index KEY resources on the sysindexes table (object ID 2). One of the two connections tries to convert a shared lock to an update lock, and trace flag 1204 output reports the statement type for both connections as UPDATE STATISTICS.

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 hotfix 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
   -------------------------------------------------------------------
   31-May-2003  18:45  2000.80.818.0      78,400  Console.exe      
   25-Jun-2003  01:01  2000.80.818.0      33,340  Dbmslpcn.dll     
   25-Apr-2003  02:12                    786,432  Distmdl.ldf
   25-Apr-2003  02:12                  2,359,296  Distmdl.mdf
   30-Jan-2003  01:55                        180  Drop_repl_hotfix.sql
   23-Jun-2003  22:40  2000.80.837.0   1,557,052  Dtsui.dll        
   23-Jun-2003  22:40  2000.80.837.0     639,552  Dtswiz.dll       
   24-Apr-2003  02:51                    747,927  Instdist.sql
   03-May-2003  01:56                      1,581  Inst_repl_hotfix.sql
   08-Feb-2003  06:40  2000.80.765.0      90,692  Msgprox.dll      
   01-Apr-2003  02:07                      1,873  Odsole.sql
   05-Apr-2003  01:46  2000.80.800.0      62,024  Odsole70.dll     
   07-May-2003  20:41  2000.80.819.0      25,144  Opends60.dll     
   02-Apr-2003  21:48  2000.80.796.0      57,904  Osql.exe         
   02-Apr-2003  23:15  2000.80.797.0     279,104  Pfutil80.dll     
   04-Aug-2003  18:17                    550,780  Procsyst.sql
   22-May-2003  22:57                     19,195  Qfe469571.sql
   11-Jul-2003  17:04                  1,084,147  Replmerg.sql
   04-Apr-2003  21:53  2000.80.798.0     221,768  Replprov.dll     
   08-Feb-2003  06:40  2000.80.765.0     307,784  Replrec.dll      
   13-Aug-2003  16:28                  1,086,797  Replsys.sql
   13-Aug-2003  16:28                    986,603  Repltran.sql
   29-Jul-2003  20:13  2000.80.819.0     492,096  Semobj.dll       
   31-May-2003  18:27  2000.80.818.0     172,032  Semobj.rll
   05-Aug-2003  21:06                    127,884  Sp3_serv_uni.sql
   01-Jun-2003  01:01  2000.80.818.0   4,215,360  Sqldmo.dll       
   07-Apr-2003  17:44                     25,172  Sqldumper.exe    
   19-Mar-2003  18:20  2000.80.789.0      28,672  Sqlevn70.rll
   02-Jul-2003  00:18  2000.80.834.0     180,736  Sqlmap70.dll     
   08-Feb-2003  06:40  2000.80.765.0      57,920  Sqlrepss.dll     
   13-Aug-2003  20:04  2000.80.851.0   7,598,161  Sqlservr.exe     
   25-Jul-2003  21:44  2000.80.845.0     590,396  Sqlsort.dll      
   08-Feb-2003  06:40  2000.80.765.0      45,644  Sqlvdi.dll       
   25-Jun-2003  01:01  2000.80.818.0      33,340  Ssmslpcn.dll     
   01-Jun-2003  01:01  2000.80.818.0      82,492  Ssnetlib.dll     
   01-Jun-2003  01:01  2000.80.818.0      25,148  Ssnmpn70.dll     
   01-Jun-2003  01:01  2000.80.818.0     158,240  Svrnetcn.dll     
   31-May-2003  18:59  2000.80.818.0      76,416  Svrnetcn.exe     
   30-Apr-2003  23:52  2000.80.816.0      45,132  Ums.dll          
   02-Jul-2003  00:19  2000.80.834.0      98,816  Xpweb70.dll

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

This fix is SQL Server build number 851, and it can only be applied to a computer that is running SQL Server 2000 Service Pack 3 (SP3) or a hotfix build that is based on SQL Server SP3.

Back to the top

STATUS

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

Back to the top

WORKAROUND

To work around this problem, do not run UPDATE STATISTICS from two connections at the same time against the same table.

Back to the top

MORE INFORMATION

This problem only occurs for explicit UPDATE STATISTICS commands or for the sp_updatestats stored procedure. (The sp_updatestats stored procedure runs UPDATE STATISTICS.) This problem does not occur because of the auto update statistics or the auto create statistics database options or because of explicit CREATE STATISTICS commands. This hotfix serializes UPDATE STATISTICS commands that act on the same table, in the same way that statistics creation and auto update statistics events are already serialized.

Back to the top