DOCUMENT:Q304329  08-MAY-2002  [odbc]
TITLE   :Fix:Microsoft Oracle ODBC Driver Crashes When TNS Does Not Exist
PRODUCT :Open Database Connectivity (ODBC)
PROD/VER::2.6,2.6 SP1,Build 2.573.6526,Build 2.573.7326
OPER/SYS:
KEYWORDS:kbDatabase kbMDAC kbODBC kbOracle kbGrpDSVCDB kbMDAC260bug kbMDAC260fix kbSQLServ2000SP

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The information in this article applies to:

 - Microsoft Data Access Components versions 2.6, 2.6 SP1 
 - Microsoft ODBC for Oracle version 2.5, versions Build 2.573.6526, Build 2.573.7326 
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SYMPTOMS
========

When connecting with an ODBC connection (with or without a data source name)
using the Microsoft ODBC driver for Oracle, if the specified Transparent Network
Substrate (TNS) name does not exist for the Oracle server, an application may
receive an access violation. This occurs whether using SQLConnect() or
SQLDriverConnect().

CAUSE
=====

This problem occurs only when ODBC connection pooling is enabled. When the
Microsoft ODBC driver for Oracle returns a connection failure (because the TNS
name does not exist), the ODBC Driver Manager pools the failed connection but
does not mark the connection as dead. The connection handle is used later and an
access violation occurs.


RESOLUTION
==========

To resolve this problem, obtain the latest service pack for SQL Server 2000, the
latest service pack for MDAC 2.6, or the MDAC hotfix referenced below: For
additional information, click the article number below to view the article in
the Microsoft Knowledge Base:

   Q290211 INF: How to Obtain the Latest SQL Server 2000 Service Pack

For additional information, click the article number below to view the article in
the Microsoft Knowledge Base:

   Q300635 INFO: How to Obtain the Latest MDAC 2.6 Service Pack

A supported fix is now available from Microsoft, but it is only intended to
correct the problem described in this article and should be applied only to
systems experiencing this specific problem. This fix may receive additional
testing at a later time, to further ensure product quality. Therefore, if you
are not severely affected by this problem, Microsoft recommends that you wait
for the next Microsoft ODBC for Oracle ODBC driver that contains this fix.

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, please go to the following
address on the World Wide Web:

   http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

NOTE: In special cases, charges that are normally incurred for support calls may
be canceled, if a Microsoft Support Professional determines that a specific
update will resolve your problem. Normal 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     
   ----------------------------------------------------------
   29-JUNE-2001   14:29  3.520.7629.0   221,456   Odbc32.dll



STATUS
======

Microsoft has confirmed this to be a problem in the Microsoft products that are
listed at the beginning of this article. This problem was first corrected in SQL
Server 2000 Service Pack 2 and MDAC 2.6 Service Pack 2.

Additional query words:

======================================================================
Keywords          : kbDatabase kbMDAC kbODBC kbOracle kbGrpDSVCDB kbMDAC260bug kbMDAC260fix kbSQLServ2000SP2Fix kbSQLServ2000preSP2Fix kbmdac260sp2fix 
Technology        : kbAudDeveloper kbODBCSearch kbMDACSearch kbMDAC260 kbODBCOracle25736526 kbMDAC260SP1 kbODBCOracle25737326 kbODBCOracle250Search
Version           : :2.6,2.6 SP1,Build 2.573.6526,Build 2.573.7326
Hardware          : x86
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

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