Under what conditions would DTC be invoked? I understand that it is between two servers, using a linked server, with four part naming schemes. Is DTC only used when the remote action is inside a transaction? Would implicit transactions enlist in a distributed transaction as well? If you call a SP on the remote server and send in an xml document with your rows to insert/update/select, would that participate in a DTC transaction?
We are contemplating using mirroring or always on in our environment and know that DTC is not supported. We are looking at what we would need to do to have our environment (which I have traced in profiler and know is using DTC transactions) changed in order to use these technologies.