To get things ready normally you need to at least do the following:
- install the Oracle drivers & reboot
- set "allow in process" on the provider in SQL
- ensure the default DTC is the clustered resource
- enabled DTC for network access and set correct authentication.
Normally things would work at this point. No such luck today though! No matter what I did I couldn't get a specific stored procedure a user wrote to without firing off the "unable to enlist" error. Other DTC transactions worked just fine.
The solution was simple (but tricky for non-Oracle DBAs); I had to install the "Oracle Services for Microsoft Transaction Server 18.104.22.168.0" service and reboot.
Now, I *could* have re-written the query but since it was already working on another QA box and the user is going to be re-working the whole solution shortly I didn't see much point. Plus I wanted to know HOW or IF it could be made to work on this cluster! ;)
Hope this helps someone else out there!