Any distributed transaction management requires 2PC in some or other form. So, we should implement 2PC for FDW keeping in mind various forms of 2PC used practically. Use that infrastructure to build XTM like capabilities for restricted postgres_fdw uses. Previously, I have requested the authors of XTM to look at my patch and provide me feedback about their requirements for implementing 2PC part of XTM. But I have not heard anything from them.
