Error with VB, Ora ODBC 8.1.6, MS Tran Server and Ora services for MTS

Question

I am getting VB error -2147168246 "Failed to enlist global transaction" from a VB middle tier component loaded in MS Tran Server. The VB error also mentions MS OLEDB Provider, however, I am using Ora ODBC 8.1.6, MS Tran Server 2.0, Ora Services for MTS (8.1.6) and Ora 8.1.6 for Win NT database. The VB middle tier component is marked as Requires Transaction. When the error occurs, the component has performed 3 SELECT's, a DELETE FROM, 3 more SELECT's, and then fails on a 4th SELECT. All of these activities are happening in this one VB component - it is not making calls to other components. Any ideas?

Answer 1

Thank you for your response. To answer your question, no, the SELECT statements do not involve any LOB's. With respect to the "Failed to enlist" error message, the dialog box mentions the Microsoft OLE DB Provider. We are using Oracle's 8.1.6 ODBC Driver and our connection string in VB 6.0 uses the DSN= syntax; we don't expicitly have the Provider= syntax in there. One of our many questions is: Given the above, is the Microsoft OLE DB Provider somehow being used, instead of Oracle's OLE DB Provider? We think not because we use Oracle Services for MTS and its trace file shows some transactions enlisted and completed, but this is a deduction - we don't really know what's happening behind the scenes. Another question we have is: When installing the Oracle 8.1.6 database on Win NT 4.0, there is a step where we must choose communication protocols. We have been selecting just TCP/IP. I read in OTN that Oracle Services for MTS talks to Microsoft's DTC using Named Pipes. We are now wondering if we should have included Named Pipes as a comm protocol when installing the DB.