ODBC Provider Incorrectly Interprets SQL_DTC_DONE Flag in Distributed Transaction (235508)

SYMPTOMS

When participating in a distributed transaction, the Microsoft OLE DB Provider for ODBC (MSDASQL) interprets values, other than SQL_DTC_DONE, to mean that the current connection is already enlisted in a distributed transaction. However, the transaction has completed, the connection has been recycled and is being reused, and is involved in a completely different transaction.

This behavior occurs primarily when connecting to a DB2 server.

CAUSE

When the Microsoft OLE DB Provider for ODBC calls ITransactionJoin::JoinTransaction, a call is being made to the SQLGetConnectAttr() function with the SQL_COPT_SS_ENLIST_IN_DTC attribute. In the DB2 driver, this returns a value other than SQL_DTC_DONE, and that is interpreted to mean the connection is still involved in a distributed transaction.

Since a connection can only be enlisted in one distributed transaction at a time, this generates a XACT_E_XTIONEXISTS return code and the following error message:

Only one transaction allowed

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 Data Access Components Service Pack 2 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/default.aspx?scid=fh;EN-US;CNTACTMS

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 should have the following file attributes or later:

   Date      Time    Version      Size    File name     Platform
   -------------------------------------------------------------
   6/9/99            2.10.4209    583KB   msdasql.dll
   6/9/99            2.10.4209     10KB   msdasqlr.dll
   6/9/99            2.10.4209    152KB   msdatl2.dll
   6/9/99            2.10.4209     87KB   msdatt.dll

MORE INFORMATION

Manual Installation

Quit any applications or services that are using the ODBC provider (MSDASQL.dll). This may include Internet Information Server (IIS), Microsoft Transaction Server (MTS), Microsoft Distributed Transaction Coordinator (DTC), and any ADO or ODBC applications.
Download the hotfix (WrongTrans.exe) into a temporary directory and run it to extract the following files:
- Msdasql.dll
- Msdasqlr.dll
- Msdatl2.dll
- Msdatt.dll
- Readme.txt
Locate and rename the current versions of the files listed in step two. These files should exist in the \Program files\Common files\System\ole db folder.
Copy the hotfix files into the same location, and restart your services and applications.

Important Notice for Microsoft Windows 95/98 Users

If you are installing this fix on to a computer running Windows 95 or a computer with the original release of Windows 98, you may need to install the Windows 98 Migration DLL included with this fix. Please carefully read the Migrate_qfe.txt file that is included in the Migration.exe file that is in the download file.