Håkan Jacobsson wrote:
> Hi,
>
> I've posted earlier about this. I had problems connecting to the two postgresql databases our company system uses
whenmigrating to JBoss 4.2.2.GA .
> Lots of exceptions about 'Generic JDBC connection can not be created' (something like that).
> I got a solution from a guy here at the mailing list. By using a JBoss database configuration file (postgres-ds.xml)
with'XA-support' we got rid of the exceptions.
> I've tried to search google to understand what this 'XA-support' really does, but I haven't found that much (other
thanan old thread 'XA-support for Postgres) dating back to 2005.
> Can someone point me to some good documentation for the XA-support for Postgres?
X/Open XA is a standard interface for performing two-phase commit across
different resource managers, like databases.
In Java-world, XA is mapped to the Java Transaction API (JTA). XA
support basically means that the driver comes with an implementation of
the javax.sql.XADataSource interface.
You need two-phase commit if you want to update two databases in a
single atomic transaction.
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com