: 1- XA JDBC driver for Postgre (needed for NexJ Express Model)

:: Hierarchy for package [http://jdbc.postgresql.org/development/privateapi/org/postgresql/xa/package-tree.html org.postgresql.xa]

:: Postgresql Limited XA Support[http://www.atomikos.com/Documentation/KnownProblems#Postgresql_Limited_XA_Support] - PostgreSQL XA support is limited in what it can do; using Postgresql is not recommended and not supported. If you do choose to use it, see this forum post for some of the problems.

::PostgreSQL HeuristicMixed Exception [http://www.atomikos.com/Documentation/KnownProblems#PostgreSQL_HeuristicMixed_Except] - On PostgreSQL make sure to set the max_prepared_transactions at least as high as the max_connections, or you get heuristic problems.