PostgreSQL OID – When Does a Table Get an OID in PostgreSQL

Constraints are only checked when you execute SQL-level DML commands such as DELETE or UPDATE. They are not checked when you effect a system catalog data change using a DDL command such as DROP TABLE. Those take a different code path internally, even though they end up modifying the same data.

As a consequence, you currently cannot do what you are trying to do. In PostgreSQL 9.3, there will be event triggers, which will address the space your problem is in.

There are two Distributed Transaction Standards Supported by the DTC. XA Transactions and OLE Transactions and recovery is implemented differently.

XA Transaction Recovery Process use xa_recover_entry of GetXaSwitch to get a list of xid from the transaction resource manager (SQL Server is a resource manager) that it then uses to rollback or commit the prepared transactions. I assume that running as NETWORKSERVICE is enough to do that based on what is documented in Disabling TIP, LU and XA Transactions

In Windows XP , Windows Server 2003, and subsequent versions you can disable XA transactions to help prevent the security risk that arises when a user-specified DLL, used by the DTC to communicate with the XA partner's transaction manager, is loaded directly into the DTC process. This situation exposes a resource manager's databases to serious data corruption and can cause Denial of Service (DOS) attacks. The disabling of XA transactions helps to protect the DTC from this DLL attack.

The recovery process for OLE is implemented a bit differently. The resource manager has a list of prepared transactions and is responsible for reenlisting them in the DTC. Have a look at the Performing Recovery section of Implementing DTC Interfaces.

_{Not sure I actually provided a definitive answer for you here but I thought this was too much for a comment.}