FIX: MSDAORA Does Not Honor the NoWorkerThread Property (814047)


The information in this article applies to:

  • Microsoft Data Access Components 2.7 SP1

SYMPTOMS

When you use the NoWorkerThread connection string property with Microsoft OLE DB Provider for Oracle (MSDAORA), worker threads are still spawned when you use the provider with distributed transactions.

CAUSE

An internal function in MSDAORA that is responsible for joining distributed transactions does not honor the NoWorkerThread property.

RESOLUTION

A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next Microsoft Data Access Components (MDAC) service pack 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 usual 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 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   
   ------------------------------------------------------
   06-Feb-2003  02:44  2.71.9031.27 221,184  Msdaora.dll

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section of this article.

MORE INFORMATION

You can use the NoWorkerThread property in a connection string with MSDAORA to avoid using a separate worker thread for each Oracle connection. By default, a worker thread is used, and this insures that all access to the Oracle OCI layer is serialized to a single worker thread for each connection. On the default mode, the thread security token of this worker thread is not set. Therefore, the worker thread inherits the process security token. If you set the NoWorkerThread property, the call to OCI occurs on the same thread as the client thread that is opening the connection. As a result, you can use the security token of the client thread (if it is set).

The following Microsoft Visual Basic Scripting Edition (VBScript) code sample demonstrates how to open a connection by using the NoWorkerThread flag with ADO:
Dim conn
set conn = createobject("adodb.connection")
conn.open "Provider=MSDAORA;User ID=MyUser;Password=MyPassword;Data Source=ORACLE92;Extended
Properties=NoWorkerThread;"
When you use distributed transactions, the NoWorkerThread property is not honored unless you apply the hotfix.
Modification Type:MajorLast Reviewed:4/7/2006
Keywords:kbQFE KBHotfixServer kbfix kbBug KB814047
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