Hope this helps. Here's how my postgresql datasource is configured in the jboss.jcml (under the JDBC section).
Do you have some evidence that Postgres supports xa semantics and provides an XADataSource implementation? I haven't found any despite some searching. Even if there is an XADataSource implementation it won't do you any good unless Postgres actually supports two phase commit. If this is the case, stick with the regular driver, it is simpler.
I'm not sure that Postgres driver supports XA, I was using an XA configuration in JBoss 2.4.4 (jboss.jcml file). But really I have a problem when I sent massive querys, I posted the problem in :
http://www.jboss.org/modules/bb/index.html?module=bb&op=viewtopic&t=forums/ I'm going to test the version JBoss-3.0.1RC1, according to response of Dain Sundstrom.
Thank you for your help.
Jose Luis Martinez
Sorry for my poor english.
PostrgeSQL does not support 2pc.